Enhanced network-link architecture for improved end-to-end latency in communication between different cloud environments

ABSTRACT

Techniques are described for creating a network-link between a first virtual network in a first cloud environment and a second virtual network in a second cloud environment. The first virtual network in the first cloud environment is created to enable a user associated with a customer tenancy in the second cloud environment to access one or more services provided in the first cloud environment. The network-link is created based on one or more link-enabling virtual networks being deployed in the first cloud environment and the second cloud environment.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a non-provisional of and claims the benefitof each of the following provisional applications. The entire contentsof each of the provisional applications listed below are incorporatedherein by reference for all purposes.

-   (1) U.S. Provisional Application No. 63/306,007, filed on Feb. 2,    2022;-   (2) U.S. Provisional Application No. 63/306,918, filed on Feb. 4,    2022;-   (3) U.S. Provisional Application No. 63/321,614, filed on Mar. 18,    2022;-   (4) U.S. Provisional Application No. 63/333,965, filed on Apr. 22,    2022;-   (5) U.S. Provisional Application No. 63/336,811, filed on Apr. 29,    2022;-   (6) U.S. Provisional Application No. 63/339,297, filed on May 6,    2022;-   (7) U.S. Provisional Application No. 63/346,004, filed on May 26,    2022;-   (8) U.S. Provisional Application No. 63/389,305, filed on Jul. 14,    2022;-   (9) U.S. Provisional Application No. 63/389,145, filed on Jul. 14,    2022; and-   (10) U.S. Provisional Application No. 63/380,326, filed on Oct. 20,    2022.

This application is also related to the following applications. Theentire contents of each of the following applications are incorporatedherein by reference for all purposes.

-   (1) Non-provisional application Ser. No. ______, titled “CONFIGURING    A NETWORK-LINK FOR ESTABLISHING COMMUNICATION BETWEEN DIFFERENT    CLOUD ENVIRONMENTS” (Atty Docket No, 088325-1352127 (342713US))    filed concurrently with the present application; and-   (2) Non-provisional application Ser. No. ______, titled    “ARCHITECTURE OF A MULTI-CLOUD CONTROL PLANE-NETWORK ADAPTOR” (Atty    Docket No, 088325-1346679 (342720US)) filed concurrently with the    present application.

FIELD

The present disclosure relates to cloud architectures, and moreparticularly to techniques for linking two cloud environments such thata user of one cloud environment can use a service provided by the othercloud environment.

BACKGROUND

The last few years have seen a dramatic increase in the adoption ofcloud services and this trend is only going to increase. Variousdifferent cloud environments are being provided by different cloudservice providers (CSPs), each cloud environment providing a set of oneor more cloud services. The set of cloud services offered by a cloudenvironment may include one or more different types of servicesincluding but not restricted to Software-as-a-Service (SaaS) services,Infrastructure-as-a-Service (IaaS) services, Platform-as-a-Service(PaaS) services, and others.

While various different cloud environments are currently available, eachcloud environment provides a closed ecosystem for its subscribingcustomers. As a result, a customer of a cloud environment is restrictedto using the services offered by that cloud environment. There is noeasy way for a customer subscribing to a cloud environment provided by aCSP to, via that cloud environment, use a service offered in a differentcloud environment provided by a different CSP. Embodiments discussedherein address these and other issues. Embodiments discussed hereinaddress these and other issues.

SUMMARY

The present disclosure relates generally to improved cloudarchitectures, and more particularly to techniques for linking twoclouds such that a user of one cloud environment can use a serviceprovided by another different cloud environment. Various embodiments aredescribed herein, including methods, systems, non-transitorycomputer-readable storage media storing programs, code, or instructionsexecutable by one or more processors, and the like. Some embodiments maybe implemented by using a computer program product, comprising computerprogram/instructions which, when executed by a processor, cause theprocessor to perform any of the methods described in the disclosure.

Embodiments of the present disclosure provide for a multi-cloud controlplane (MCCP) framework that provisions for capabilities to deliverservices of a particular cloud network (e.g., Oracle CloudInfrastructure (OCI)) to users on other clouds (e.g., in MicrosoftAzure). The MCCP framework allows users (of other cloud environment(s))to access services (e.g., PaaS services) of a cloud environment, whileproviding with a user experience as close as possible to that of thenative cloud environment(s) of the user. A key value proposition to MCCPis that customers will be able to experience the full data planecapabilities of the services in external clouds.

One embodiment of the present disclosure is directed to a methodcomprising: receiving, by a multi-cloud infrastructure included in afirst cloud environment, a request to create a network-link between afirst virtual network in the first cloud environment and a secondvirtual network in a second cloud environment, the first virtual networkin the first cloud environment being previously created to enable a userassociated with a customer tenancy in the second cloud environment toaccess one or more services provided in the first cloud environment; andcreating the network-link between the first virtual network in the firstcloud environment and the second virtual network in the second cloudenvironment using a plurality of link-enabling virtual networks, whereina first link-enabling virtual network from the plurality oflink-enabling virtual networks is placed in the second cloud environmentand a second link-enabling virtual network from the plurality oflink-enabling virtual networks is placed in the first cloud environment.

An aspect of the present disclosure provides for a computing devicecomprising one or more data processors, and a non-transitory computerreadable storage medium containing instructions which, when executed onthe one or more data processors, cause the computing device to performpart or all of one or more methods disclosed herein.

Another aspect of the present disclosure provides for a computer-programproduct tangibly embodied in a non-transitory machine-readable storagemedium, including instructions configured to cause one or more dataprocessors to perform part or all of one or more methods disclosedherein.

The foregoing, together with other features and embodiments will becomemore apparent upon referring to the following specification, claims, andaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, embodiments, and advantages of the present disclosure arebetter understood when the following Detailed Description is read withreference to the accompanying drawings.

FIG. 1 is a high-level diagram of a distributed environment showing avirtual or overlay cloud network hosted by a cloud service providerinfrastructure according to certain embodiments.

FIG. 2 depicts a simplified architectural diagram of the physicalcomponents in the physical network within CSPI according to certainembodiments.

FIG. 3 shows an example arrangement within CSPI where a host machine isconnected to multiple network virtualization devices (NVDs) according tocertain embodiments.

FIG. 4 depicts connectivity between a host machine and an NVD forproviding I/O virtualization for supporting multitenancy according tocertain embodiments.

FIG. 5 depicts a simplified block diagram of a physical network providedby a CSPI according to certain embodiments.

FIG. 6 depicts a simplified high-level diagram of a distributedenvironment comprising multiple cloud environments provided by differentcloud service providers (CSPs) wherein the cloud environments include aparticular cloud environment that provides specialized infrastructurethat enables one or more cloud services provided by that particularcloud environment to be used by customers of other cloud environmentsaccording to certain embodiments.

FIG. 7 depicts an exemplary high-level architecture of a multi-cloudcontrol plane (MCCP), according to some embodiments.

FIGS. 8A and 8B depict exemplary processes for linking two user accountsin different cloud environments, according to some embodiments.

FIG. 9 depicts an exemplary system diagram illustrating components of amulti-cloud control plane (MCCP) according to some embodiments.

FIG. 10 depicts a high-level block diagram of a network-link componentaccording to certain embodiments.

FIG. 11 depicts a detailed architecture of a network-link according tocertain embodiments.

FIGS. 12A and 12B depict exemplary latency values observed for thearchitecture of the network-link of FIG. 11 , according to certainembodiments.

FIG. 12C depicts an exemplary flowchart illustrating a process ofestablishing a network-link according to certain embodiments.

FIG. 13 depicts another detailed architecture of a network-linkaccording to certain embodiments.

FIG. 14A depicts exemplary latency values observed for the architectureof the network-link of FIG. 13 , according to certain embodiments.

FIG. 14B depicts another exemplary flowchart illustrating a process ofestablishing a network-link according to certain embodiments.

FIG. 15 depicts a system diagram of a multi-cloud service control plane,according to certain embodiments.

FIG. 16A depicts a swim diagram illustrating interactions of themulti-cloud service control plane with different cloud environments,according to certain embodiments.

FIG. 16B depicts an exemplary flowchart illustrating a process performedby the multi-cloud service control plane, according to certainembodiments.

FIG. 17A depicts an exemplary placement strategy of compute instances inavailability domains of different cloud environments, according tocertain embodiments.

FIG. 17B depicts an exemplary flowchart illustrating a process performedby the multi-cloud service control plane in determining availabilitydomains of different cloud environments in which compute instances areto be placed, according to certain embodiments.

FIG. 18 is a block diagram illustrating one pattern for implementing acloud infrastructure as a service system, according to at least oneembodiment.

FIG. 19 is a block diagram illustrating another pattern for implementinga cloud infrastructure as a service system, according to at least oneembodiment.

FIG. 20 is a block diagram illustrating another pattern for implementinga cloud infrastructure as a service system, according to at least oneembodiment.

FIG. 21 is a block diagram illustrating another pattern for implementinga cloud infrastructure as a service system, according to at least oneembodiment.

FIG. 22 is a block diagram illustrating an example computer system,according to at least one embodiment.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, specificdetails are set forth in order to provide a thorough understanding ofcertain embodiments. However, it will be apparent that variousembodiments may be practiced without these specific details. The figuresand description are not intended to be restrictive. The word “exemplary”is used herein to mean “serving as an example, instance, orillustration.” Any embodiment or design described herein as “exemplary”is not necessarily to be construed as preferred or advantageous overother embodiments or designs.

The present disclosure relates generally to improved cloudarchitectures, and more particularly to techniques for linking twoclouds such that a user of one cloud environment can use a serviceprovided by another different cloud environment. Various embodiments aredescribed herein, including methods, systems, non-transitorycomputer-readable storage media storing programs, code, or instructionsexecutable by one or more processors, and the like. Some embodiments maybe implemented by using a computer program product, comprising computerprogram/instructions which, when executed by a processor, cause theprocessor to perform any of the methods described in the disclosure.

Embodiments of the present disclosure provide for a multi-cloud controlplane (MCCP) framework that provisions for capabilities to deliverservices of a particular cloud network (e.g., Oracle CloudInfrastructure (OCI)) to users on other clouds (e.g., in MicrosoftAzure). The MCCP framework allows users (of other cloud environment(s))to access services (e.g., PaaS services) of a cloud environment, whileproviding with a user experience as close as possible to that of thenative cloud environment(s) of the user. A key value proposition to MCCPis that customers will be able to experience the full data planecapabilities of the services in external clouds.

The MCCP enables users of a second cloud infrastructure (e.g., Azureusers) to make use of resources (e.g., database resources) provided by afirst cloud infrastructure (e.g., OCI) in a way that is transparent tothe user. Specifically, the services provided by the first cloudinfrastructure appear as “native” services in the second cloudinfrastructure. This allows customers of the second cloud infrastructureto natively access services provided by the first cloud infrastructure.As will be described below with reference to FIGS. 6-17B, the MCCP is acollection of microservices executed in the first cloud infrastructurewhich exposes resources of the first cloud infrastructure to be utilizedby external cloud users (e.g., users of the second cloudinfrastructure). Each of the microservices acts as a proxy providingcommunication to resources provided by the first cloud infrastructure.

Examples of Cloud Networks

The term cloud service is generally used to refer to a service that ismade available by a cloud services provider (CSP) to users or customerson demand (e.g., via a subscription model) using systems andinfrastructure (cloud infrastructure) provided by the CSP. Typically,the servers and systems that make up the CSP's infrastructure areseparate from the customer's own on-premises servers and systems.Customers can thus avail themselves of cloud services provided by theCSP without having to purchase separate hardware and software resourcesfor the services. Cloud services are designed to provide a subscribingcustomer easy, scalable access to applications and computing resourceswithout the customer having to invest in procuring the infrastructurethat is used for providing the services.

There are several cloud service providers that offer various types ofcloud services. There are various different types or models of cloudservices including Software-as-a-Service (SaaS), Platform-as-a-Service(PaaS), Infrastructure-as-a-Service (IaaS), and others.

A customer can subscribe to one or more cloud services provided by aCSP. The customer can be any entity such as an individual, anorganization, an enterprise, and the like. When a customer subscribes toor registers for a service provided by a CSP, a tenancy or an account iscreated for that customer. The customer can then, via this account,access the subscribed-to one or more cloud resources associated with theaccount.

As noted above, infrastructure as a service (IaaS) is one particulartype of cloud computing service. In an IaaS model, the CSP providesinfrastructure (referred to as cloud services provider infrastructure orCSPI) that can be used by customers to build their own customizablenetworks and deploy customer resources. The customer's resources andnetworks are thus hosted in a distributed environment by infrastructureprovided by a CSP. This is different from traditional computing, wherethe customer's resources and networks are hosted by infrastructureprovided by the customer.

The CSPI may comprise interconnected high-performance compute resourcesincluding various host machines, memory resources, and network resourcesthat form a physical network, which is also referred to as a substratenetwork or an underlay network. The resources in CSPI may be spreadacross one or more data centers that may be geographically spread acrossone or more geographical regions. Virtualization software may beexecuted by these physical resources to provide a virtualizeddistributed environment. The virtualization creates an overlay network(also known as a software-based network, a software-defined network, ora virtual network) over the physical network. The CSPI physical networkprovides the underlying basis for creating one or more overlay orvirtual networks on top of the physical network. The physical network(or substrate network or underlay network) comprises physical networkdevices such as physical switches, routers, computers and host machines,and the like. An overlay network is a logical (or virtual) network thatruns on top of a physical substrate network. A given physical networkcan support one or multiple overlay networks. Overlay networks typicallyuse encapsulation techniques to differentiate between traffic belongingto different overlay networks. A virtual or overlay network is alsoreferred to as a virtual cloud network (VCN). The virtual networks areimplemented using software virtualization technologies (e.g.,hypervisors, virtualization functions implemented by networkvirtualization devices (NVDs) (e.g., smartNICs), top-of-rack (TOR)switches, smart TORs that implement one or more functions performed byan NVD, and other mechanisms) to create layers of network abstractionthat can be run on top of the physical network. Virtual networks cantake on many forms, including peer-to-peer networks, IP networks, andothers. Virtual networks are typically either Layer-3 IP networks orLayer-2 VLANs. This method of virtual or overlay networking is oftenreferred to as virtual or overlay Layer-3 networking. Examples ofprotocols developed for virtual networks include IP-in-IP (or GenericRouting Encapsulation (GRE)) Virtual Extensible LAN (VXLAN—IETF RFC7348), Virtual Private Networks (VPNs) (e.g., MPLS Layer-3 VirtualPrivate Networks (RFC 4364)), VMware's NSX, GENEVE (Generic NetworkVirtualization Encapsulation), and others.

For IaaS, the infrastructure (CSPI) provided by a CSP can be configuredto provide virtualized computing resources over a public network (e.g.,the Internet). In an IaaS model, a cloud computing services provider canhost the infrastructure components (e.g., servers, storage devices,network nodes (e.g., hardware), deployment software, platformvirtualization (e.g., a hypervisor layer), or the like). In some cases,an IaaS provider may also supply a variety of services to accompanythose infrastructure components (e.g., billing, monitoring, logging,security, load balancing and clustering, etc.). Thus, as these servicesmay be policy-driven, IaaS users may be able to implement policies todrive load balancing to maintain application availability andperformance. CSPI provides infrastructure and a set of complementarycloud services that enable customers to build and run a wide range ofapplications and services in a highly available hosted distributedenvironment. CSPI offers high-performance compute resources andcapabilities and storage capacity in a flexible virtual network that issecurely accessible from various networked locations such as from acustomer's on-premises network. When a customer subscribes to orregisters for an IaaS service provided by a CSP, the tenancy created forthat customer is a secure and isolated partition within the CSPI wherethe customer can create, organize, and administer their cloud resources.

Customers can build their own virtual networks using compute, memory,and networking resources provided by CSPI. One or more customerresources or workloads, such as compute instances, can be deployed onthese virtual networks. For example, a customer can use resourcesprovided by CSPI to build one or multiple customizable and privatevirtual network(s) referred to as virtual cloud networks (VCNs). Acustomer can deploy one or more customer resources, such as computeinstances, on a customer VCN. Compute instances can take the form ofvirtual machines, bare metal instances, and the like. The CSPI thusprovides infrastructure and a set of complementary cloud services thatenable customers to build and run a wide range of applications andservices in a highly available virtual hosted environment. The customerdoes not manage or control the underlying physical resources provided byCSPI but has control over operating systems, storage, and deployedapplications; and possibly limited control of select networkingcomponents (e.g., firewalls).

The CSP may provide a console that enables customers and networkadministrators to configure, access, and manage resources deployed inthe cloud using CSPI resources. In certain embodiments, the consoleprovides a web-based user interface that can be used to access andmanage CSPI. In some implementations, the console is a web-basedapplication provided by the CSP.

CSPI may support single-tenancy or multi-tenancy architectures. In asingle tenancy architecture, a software (e.g., an application, adatabase) or a hardware component (e.g., a host machine or a server)serves a single customer or tenant. In a multi-tenancy architecture, asoftware or a hardware component serves multiple customers or tenants.Thus, in a multi-tenancy architecture, CSPI resources are shared betweenmultiple customers or tenants. In a multi-tenancy situation, precautionsare taken, and safeguards put in place within CSPI to ensure that eachtenant's data is isolated and remains invisible to other tenants.

In a physical network, a network endpoint (“endpoint”) refers to acomputing device or system that is connected to a physical network andcommunicates back and forth with the network to which it is connected. Anetwork endpoint in the physical network may be connected to a LocalArea Network (LAN), a Wide Area Network (WAN), or other type of physicalnetwork. Examples of traditional endpoints in a physical network includemodems, hubs, bridges, switches, routers, and other networking devices,physical computers (or host machines), and the like. Each physicaldevice in the physical network has a fixed network address that can beused to communicate with the device. This fixed network address can be aLayer-2 address (e.g., a MAC address), a fixed Layer-3 address (e.g., anIP address), and the like. In a virtualized environment or in a virtualnetwork, the endpoints can include various virtual endpoints such asvirtual machines that are hosted by components of the physical network(e.g., hosted by physical host machines). These endpoints in the virtualnetwork are addressed by overlay addresses such as overlay Layer-2addresses (e.g., overlay MAC addresses) and overlay Layer-3 addresses(e.g., overlay IP addresses). Network overlays enable flexibility byallowing network managers to move around the overlay addressesassociated with network endpoints using software management (e.g., viasoftware implementing a control plane for the virtual network).Accordingly, unlike in a physical network, in a virtual network, anoverlay address (e.g., an overlay IP address) can be moved from oneendpoint to another using network management software. Since the virtualnetwork is built on top of a physical network, communications betweencomponents in the virtual network involves both the virtual network andthe underlying physical network. In order to facilitate suchcommunications, the components of CSPI are configured to learn and storemappings that map overlay addresses in the virtual network to actualphysical addresses in the substrate network, and vice versa. Thesemappings are then used to facilitate the communications. Customertraffic is encapsulated to facilitate routing in the virtual network.

Accordingly, physical addresses (e.g., physical IP addresses) areassociated with components in physical networks and overlay addresses(e.g., overlay IP addresses) are associated with entities in virtual oroverlay networks. A physical IP address is an IP address associated witha physical device (e.g., a network device) in the substrate or physicalnetwork. For example, each NVD has an associated physical IP address. Anoverlay IP address is an overlay address associated with an entity in anoverlay network, such as with a compute instance in a customer's virtualcloud network (VCN). Two different customers or tenants, each with theirown private VCNs can potentially use the same overlay IP address intheir VCNs without any knowledge of each other. Both the physical IPaddresses and overlay IP addresses are types of real IP addresses. Theseare separate from virtual IP addresses. A virtual IP address istypically a single IP address that is represents or maps to multiplereal IP addresses. A virtual IP address provides a 1-to-many mappingbetween the virtual IP address and multiple real IP addresses. Forexample, a load balancer may use a VIP to map to or represent multipleservers, each server having its own real IP address.

The cloud infrastructure or CSPI is physically hosted in one or moredata centers in one or more regions around the world. The CSPI mayinclude components in the physical or substrate network and virtualizedcomponents (e.g., virtual networks, compute instances, virtual machines,etc.) that are in a virtual network built on top of the physical networkcomponents. In certain embodiments, the CSPI is organized and hosted inrealms, regions, and availability domains. A region is typically alocalized geographic area that contains one or more data centers.Regions are generally independent of each other and can be separated byvast distances, for example, across countries or even continents. Forexample, a first region may be in Australia, another one in Japan, yetanother one in India, and the like. CSPI resources are divided amongregions such that each region has its own independent subset of CSPIresources. Each region may provide a set of core infrastructure servicesand resources, such as, compute resources (e.g., bare metal servers,virtual machine, containers and related infrastructure, etc.); storageresources (e.g., block volume storage, file storage, object storage,archive storage); networking resources (e.g., virtual cloud networks(VCNs), load balancing resources, connections to on-premise networks),database resources; edge networking resources (e.g., DNS); and accessmanagement and monitoring resources, and others. Each region generallyhas multiple paths connecting it to other regions in the realm.

Generally, an application is deployed in a region (i.e., deployed oninfrastructure associated with that region) where it is most heavilyused, because using nearby resources is faster than using distantresources. Applications can also be deployed in different regions forvarious reasons, such as redundancy to mitigate the risk of region-wideevents such as large weather systems or earthquakes, to meet varyingrequirements for legal jurisdictions, tax domains, and other business orsocial criteria, and the like.

The data centers within a region can be further organized and subdividedinto availability domains (ADs). An availability domain may correspondto one or more data centers located within a region. A region can becomposed of one or more availability domains. In such a distributedenvironment, CSPI resources are either region-specific, such as avirtual cloud network (VCN), or availability domain-specific, such as acompute instance.

ADs within a region are isolated from each other, fault tolerant, andare configured such that they are very unlikely to fail simultaneously.This is achieved by the ADs not sharing critical infrastructureresources such as networking, physical cables, cable paths, cable entrypoints, etc., such that a failure at one AD within a region is unlikelyto impact the availability of the other ADs within the same region. TheADs within the same region may be connected to each other by a lowlatency, high bandwidth network, which makes it possible to providehigh-availability connectivity to other networks (e.g., the Internet,customers' on-premises networks, etc.) and to build replicated systemsin multiple ADs for both high-availability and disaster recovery. Cloudservices use multiple ADs to ensure high availability and to protectagainst resource failure. As the infrastructure provided by the IaaSprovider grows, more regions and ADs may be added with additionalcapacity. Traffic between availability domains is usually encrypted.

In certain embodiments, regions are grouped into realms. A realm is alogical collection of regions. Realms are isolated from each other anddo not share any data. Regions in the same realm may communicate witheach other, but regions in different realms cannot. A customer's tenancyor account with the CSP exists in a single realm and can be spreadacross one or more regions that belong to that realm. Typically, when acustomer subscribes to an IaaS service, a tenancy or account is createdfor that customer in the customer-specified region (referred to as the“home” region) within a realm. A customer can extend the customer'stenancy across one or more other regions within the realm. A customercannot access regions that are not in the realm where the customer'stenancy exists.

An IaaS provider can provide multiple realms, each realm catered to aparticular set of customers or users. For example, a commercial realmmay be provided for commercial customers. As another example, a realmmay be provided for a specific country for customers within thatcountry. As yet another example, a government realm may be provided fora government, and the like. For example, the government realm may becatered for a specific government and may have a heightened level ofsecurity than a commercial realm. For example, Oracle CloudInfrastructure (OCI) currently offers a realm for commercial regions andtwo realms (e.g., FedRAMP authorized and IL5 authorized) for governmentcloud regions.

In certain embodiments, an AD can be subdivided into one or more faultdomains. A fault domain is a grouping of infrastructure resources withinan AD to provide anti-affinity. Fault domains allow for the distributionof compute instances such that the instances are not on the samephysical hardware within a single AD. This is known as anti-affinity. Afault domain refers to a set of hardware components (computers,switches, and more) that share a single point of failure. A compute poolis logically divided up into fault domains. Due to this, a hardwarefailure or compute hardware maintenance event that affects one faultdomain does not affect instances in other fault domains. Depending onthe embodiment, the number of fault domains for each AD may vary. Forinstance, in certain embodiments each AD contains three fault domains. Afault domain acts as a logical data center within an AD.

When a customer subscribes to an IaaS service, resources from CSPI areprovisioned for the customer and associated with the customer's tenancy.The customer can use these provisioned resources to build privatenetworks and deploy resources on these networks. The customer networksthat are hosted in the cloud by the CSPI are referred to as virtualcloud networks (VCNs). A customer can set up one or more virtual cloudnetworks (VCNs) using CSPI resources allocated for the customer. A VCNis a virtual or software defined private network. The customer resourcesthat are deployed in the customer's VCN can include compute instances(e.g., virtual machines, bare-metal instances) and other resources.These compute instances may represent various customer workloads such asapplications, load balancers, databases, and the like. A computeinstance deployed on a VCN can communicate with publicly accessibleendpoints (“public endpoints”) over a public network such as theInternet, with other instances in the same VCN or other VCNs (e.g., thecustomer's other VCNs, or VCNs not belonging to the customer), with thecustomer's on-premise data centers or networks, and with serviceendpoints, and other types of endpoints.

The CSP may provide various services using the CSPI. In some instances,customers of CSPI may themselves act like service providers and provideservices using CSPI resources. A service provider may expose a serviceendpoint, which is characterized by identification information (e.g., anIP Address, a DNS name and port). A customer's resource (e.g., a computeinstance) can consume a particular service by accessing a serviceendpoint exposed by the service for that particular service. Theseservice endpoints are generally endpoints that are publicly accessibleby users using public IP addresses associated with the endpoints via apublic communication network such as the Internet. Network endpointsthat are publicly accessible are also sometimes referred to as publicendpoints.

In certain embodiments, a service provider may expose a service via anendpoint (sometimes referred to as a service endpoint) for the service.Customers of the service can then use this service endpoint to accessthe service. In certain implementations, a service endpoint provided fora service can be accessed by multiple customers that intend to consumethat service. In other implementations, a dedicated service endpoint maybe provided for a customer such that only that customer can access theservice using that dedicated service endpoint.

In certain embodiments, when a VCN is created, it is associated with aprivate overlay Classless Inter-Domain Routing (CIDR) address space,which is a range of private overlay IP addresses that are assigned tothe VCN (e.g., 10.0/16). A VCN includes associated subnets, routetables, and gateways. A VCN resides within a single region but can spanone or more or all of the region's availability domains. A gateway is avirtual interface that is configured for a VCN and enables communicationof traffic to and from the VCN to one or more endpoints outside the VCN.One or more different types of gateways may be configured for a VCN toenable communication to and from different types of endpoints.

A VCN can be subdivided into one or more sub-networks such as one ormore subnets. A subnet is thus a unit of configuration or a subdivisionthat can be created within a VCN. A VCN can have one or multiplesubnets. Each subnet within a VCN is associated with a contiguous rangeof overlay IP addresses (e.g., 10.0.0.0/24 and 10.0.1.0/24) that do notoverlap with other subnets in that VCN, and which represent an addressspace subset within the address space of the VCN.

Each compute instance is associated with a virtual network interfacecard (VNIC), that enables the compute instance to participate in asubnet of a VCN. A VNIC is a logical representation of physical NetworkInterface Card (NIC). In general. a VNIC is an interface between anentity (e.g., a compute instance, a service) and a virtual network. AVNIC exists in a subnet, has one or more associated IP addresses, andassociated security rules or policies. A VNIC is equivalent to a Layer-2port on a switch. A VNIC is attached to a compute instance and to asubnet within a VCN. A VNIC associated with a compute instance enablesthe compute instance to be a part of a subnet of a VCN and enables thecompute instance to communicate (e.g., send and receive packets) withendpoints that are on the same subnet as the compute instance, withendpoints in different subnets in the VCN, or with endpoints outside theVCN. The VNIC associated with a compute instance thus determines how thecompute instance connects with endpoints inside and outside the VCN. AVNIC for a compute instance is created and associated with that computeinstance when the compute instance is created and added to a subnetwithin a VCN. For a subnet comprising a set of compute instances, thesubnet contains the VNICs corresponding to the set of compute instances,each VNIC attached to a compute instance within the set of computerinstances.

Each compute instance is assigned a private overlay IP address via theVNIC associated with the compute instance. This private overlay IPaddress is assigned to the VNIC that is associated with the computeinstance when the compute instance is created and used for routingtraffic to and from the compute instance. All VNICs in a given subnetuse the same route table, security lists, and DHCP options. As describedabove, each subnet within a VCN is associated with a contiguous range ofoverlay IP addresses (e.g., 10.0.0.0/24 and 10.0.1.0/24) that do notoverlap with other subnets in that VCN, and which represent an addressspace subset within the address space of the VCN. For a VNIC on aparticular subnet of a VCN, the private overlay IP address that isassigned to the VNIC is an address from the contiguous range of overlayIP addresses allocated for the subnet.

In certain embodiments, a compute instance may optionally be assignedadditional overlay IP addresses in addition to the private overlay IPaddress, such as, for example, one or more public IP addresses if in apublic subnet. These multiple addresses are assigned either on the sameVNIC or over multiple VNICs that are associated with the computeinstance. Each instance however has a primary VNIC that is createdduring instance launch and is associated with the overlay private IPaddress assigned to the instance—this primary VNIC cannot be removed.Additional VNICs, referred to as secondary VNICs, can be added to anexisting instance in the same availability domain as the primary VNIC.All the VNICs are in the same availability domain as the instance. Asecondary VNIC can be in a subnet in the same VCN as the primary VNIC,or in a different subnet that is either in the same VCN or a differentone.

A compute instance may optionally be assigned a public IP address if itis in a public subnet. A subnet can be designated as either a publicsubnet or a private subnet at the time the subnet is created. A privatesubnet means that the resources (e.g., compute instances) and associatedVNICs in the subnet cannot have public overlay IP addresses. A publicsubnet means that the resources and associated VNICs in the subnet canhave public IP addresses. A customer can designate a subnet to existeither in a single availability domain or across multiple availabilitydomains in a region or realm.

As described above, a VCN may be subdivided into one or more subnets. Incertain embodiments, a Virtual Router (VR) configured for the VCN(referred to as the VCN VR or just VR) enables communications betweenthe subnets of the VCN. For a subnet within a VCN, the VR represents alogical gateway for that subnet that enables the subnet (i.e., thecompute instances on that subnet) to communicate with endpoints on othersubnets within the VCN, and with other endpoints outside the VCN. TheVCN VR is a logical entity that is configured to route traffic betweenVNICs in the VCN and virtual gateways (“gateways”) associated with theVCN. Gateways are further described below with respect to FIG. 1 . A VCNVR is a Layer-3/IP Layer concept. In one embodiment, there is one VCN VRfor a VCN where the VCN VR has potentially an unlimited number of portsaddressed by IP addresses, with one port for each subnet of the VCN. Inthis manner, the VCN VR has a different IP address for each subnet inthe VCN that the VCN VR is attached to. The VR is also connected to thevarious gateways configured for a VCN. In certain embodiments, aparticular overlay IP address from the overlay IP address range for asubnet is reserved for a port of the VCN VR for that subnet. Forexample, consider a VCN having two subnets with associated addressranges 10.0/16 and 10.1/16, respectively. For the first subnet withinthe VCN with address range 10.0/16, an address from this range isreserved for a port of the VCN VR for that subnet. In some instances,the first IP address from the range may be reserved for the VCN VR. Forexample, for the subnet with overlay IP address range 10.0/16, IPaddress 10.0.0.1 may be reserved for a port of the VCN VR for thatsubnet. For the second subnet within the same VCN with address range10.1/16, the VCN VR may have a port for that second subnet with IPaddress 10.1.0.1. The VCN VR has a different IP address for each of thesubnets in the VCN.

In some other embodiments, each subnet within a VCN may have its ownassociated VR that is addressable by the subnet using a reserved ordefault IP address associated with the VR. The reserved or default IPaddress may, for example, be the first IP address from the range of IPaddresses associated with that subnet. The VNICs in the subnet cancommunicate (e.g., send and receive packets) with the VR associated withthe subnet using this default or reserved IP address. In such anembodiment, the VR is the ingress/egress point for that subnet. The VRassociated with a subnet within the VCN can communicate with other VRsassociated with other subnets within the VCN. The VRs can alsocommunicate with gateways associated with the VCN. The VR function for asubnet is running on or executed by one or more NVDs executing VNICsfunctionality for VNICs in the subnet.

Route tables, security rules, and DHCP options may be configured for aVCN. Route tables are virtual route tables for the VCN and include rulesto route traffic from subnets within the VCN to destinations outside theVCN by way of gateways or specially configured instances. A VCN's routetables can be customized to control how packets are forwarded/routed toand from the VCN. DHCP options refers to configuration information thatis automatically provided to the instances when they boot up.

Security rules configured for a VCN represent overlay firewall rules forthe VCN. The security rules can include ingress and egress rules, andspecify the types of traffic (e.g., based upon protocol and port) thatis allowed in and out of the instances within the VCN. The customer canchoose whether a given rule is stateful or stateless. For instance, thecustomer can allow incoming SSH traffic from anywhere to a set ofinstances by setting up a stateful ingress rule with source CIDR0.0.0.0/0, and destination TCP port 22. Security rules can beimplemented using network security groups or security lists. A networksecurity group consists of a set of security rules that apply only tothe resources in that group. A security list, on the other hand,includes rules that apply to all the resources in any subnet that usesthe security list. A VCN may be provided with a default security listwith default security rules. DHCP options configured for a VCN provideconfiguration information that is automatically provided to theinstances in the VCN when the instances boot up.

In certain embodiments, the configuration information for a VCN isdetermined and stored by a VCN Control Plane. The configurationinformation for a VCN may include, for example, information about theaddress range associated with the VCN, subnets within the VCN andassociated information, one or more VRs associated with the VCN, computeinstances in the VCN and associated VNICs, NVDs executing the variousvirtualization network functions (e.g., VNICs, VRs, gateways) associatedwith the VCN, state information for the VCN, and other VCN-relatedinformation. In certain embodiments, a VCN Distribution Servicepublishes the configuration information stored by the VCN Control Plane,or portions thereof, to the NVDs. The distributed information may beused to update information (e.g., forwarding tables, routing tables,etc.) stored and used by the NVDs to forward packets to and from thecompute instances in the VCN.

In certain embodiments, the creation of VCNs and subnets are handled bya VCN Control Plane (CP), and the launching of compute instances ishandled by a Compute Control Plane. The Compute Control Plane isresponsible for allocating the physical resources for the computeinstance and then calls the VCN Control Plane to create and attach VNICsto the compute instance. The VCN CP also sends VCN data mappings to theVCN data plane that is configured to perform packet forwarding androuting functions. In certain embodiments, the VCN CP provides adistribution service that is responsible for providing updates to theVCN data plane. Examples of a VCN Control Plane are also depicted inFIGS. 6, 7, 8, and 9 (see references 616, 716, 816, and 916) anddescribed below.

A customer may create one or more VCNs using resources hosted by CSPI. Acompute instance deployed on a customer VCN may communicate withdifferent endpoints. These endpoints can include endpoints that arehosted by CSPI and endpoints outside CSPI.

Various different architectures for implementing cloud-based serviceusing CSPI are depicted in FIGS. 1, 2, 3, 4, 5, and 18-22 , and aredescribed below. FIG. 1 is a high-level diagram of a distributedenvironment 100 showing an overlay or customer VCN hosted by CSPIaccording to certain embodiments. The distributed environment depictedin FIG. 1 includes multiple components in the overlay network.Distributed environment 100 depicted in FIG. 1 is merely an example andis not intended to unduly limit the scope of claimed embodiments. Manyvariations, alternatives, and modifications are possible. For example,in some implementations, the distributed environment depicted in FIG. 1may have more or fewer systems or components than those shown in FIG. 1, may combine two or more systems, or may have a different configurationor arrangement of systems.

As shown in the example depicted in FIG. 1 , distributed environment 100comprises CSPI 101 that provides services and resources that customerscan subscribe to and use to build their virtual cloud networks (VCNs).In certain embodiments, CSPI 101 offers IaaS services to subscribingcustomers. The data centers within CSPI 101 may be organized into one ormore regions. One example region “Region US” 102 is shown in FIG. 1 . Acustomer has configured a customer VCN c/o Oracle InternationalCorporation for region 102. The customer may deploy various computeinstances on VCN 104, where the compute instances may include virtualmachines or bare metal instances. Examples of instances includeapplications, database, load balancers, and the like.

In the embodiment depicted in FIG. 1 , customer VCN 104 comprises twosubnets, namely, “Subnet-1” and “Subnet-2”, each subnet with its ownCIDR IP address range. In FIG. 1 , the overlay IP address range forSubnet-1 is 10.0/16 and the address range for Subnet-2 is 10.1/16. A VCNVirtual Router 105 represents a logical gateway for the VCN that enablescommunications between subnets of the VCN 104, and with other endpointsoutside the VCN. VCN VR 105 is configured to route traffic between VNICsin VCN 104 and gateways associated with VCN 104. VCN VR 105 provides aport for each subnet of VCN 104. For example, VR 105 may provide a portwith IP address 10.0.0.1 for Subnet-1 and a port with IP address10.1.0.1 for Subnet-2.

Multiple compute instances may be deployed on each subnet, where thecompute instances can be virtual machine instances, and/or bare metalinstances. The compute instances in a subnet may be hosted by one ormore host machines within CSPI 101. A compute instance participates in asubnet via a VNIC associated with the compute instance. For example, asshown in FIG. 1 , a compute instance C1 is part of Subnet-1 via a VNICassociated with the compute instance. Likewise, compute instance C2 ispart of Subnet-1 via a VNIC associated with C2. In a similar manner,multiple compute instances, which may be virtual machine instances orbare metal instances, may be part of Subnet-1. Via its associated VNIC,each compute instance is assigned a private overlay IP address and a MACaddress. For example, in FIG. 1 , compute instance C1 has an overlay IPaddress of 10.0.0.2 and a MAC address of M1, while compute instance C2has a private overlay IP address of 10.0.0.3 and a MAC address of M2.Each compute instance in Subnet-1, including compute instances C1 andC2, has a default route to VCN VR 105 using IP address 10.0.0.1, whichis the IP address for a port of VCN VR 105 for Subnet-1.

Subnet-2 can have multiple compute instances deployed on it, includingvirtual machine instances and/or bare metal instances. For example, asshown in FIG. 1 , compute instances D1 and D2 are part of Subnet-2 viaVNICs associated with the respective compute instances. In theembodiment depicted in FIG. 1 , compute instance D1 has an overlay IPaddress of 10.1.0.2 and a MAC address of MM1, while compute instance D2has a private overlay IP address of 10.1.0.3 and a MAC address of MM2.Each compute instance in Subnet-2, including compute instances D1 andD2, has a default route to VCN VR 105 using IP address 10.1.0.1, whichis the IP address for a port of VCN VR 105 for Subnet-2.

VCN A 104 may also include one or more load balancers. For example, aload balancer may be provided for a subnet and may be configured to loadbalance traffic across multiple compute instances on the subnet. A loadbalancer may also be provided to load balance traffic across subnets inthe VCN.

A particular compute instance deployed on VCN 104 can communicate withvarious different endpoints. These endpoints may include endpoints thatare hosted by CSPI 200 and endpoints outside CSPI 200. Endpoints thatare hosted by CSPI 101 may include: an endpoint on the same subnet asthe particular compute instance (e.g., communications between twocompute instances in Subnet-1); an endpoint on a different subnet butwithin the same VCN (e.g., communication between a compute instance inSubnet-1 and a compute instance in Subnet-2); an endpoint in a differentVCN in the same region (e.g., communications between a compute instancein Subnet-1 and an endpoint in a VCN in the same region 106 or 110,communications between a compute instance in Subnet-1 and an endpoint inservice network 110 in the same region); or an endpoint in a VCN in adifferent region (e.g., communications between a compute instance inSubnet-1 and an endpoint in a VCN in a different region 108). A computeinstance in a subnet hosted by CSPI 101 may also communicate withendpoints that are not hosted by CSPI 101 (i.e., are outside CSPI 101).These outside endpoints include endpoints in the customer's on-premisesnetwork 116, endpoints within other remote cloud hosted networks 118,public endpoints 114 accessible via a public network such as theInternet, and other endpoints.

Communications between compute instances on the same subnet arefacilitated using VNICs associated with the source compute instance andthe destination compute instance. For example, compute instance C1 inSubnet-1 may want to send packets to compute instance C2 in Subnet-1.For a packet originating at a source compute instance and whosedestination is another compute instance in the same subnet, the packetis first processed by the VNIC associated with the source computeinstance. Processing performed by the VNIC associated with the sourcecompute instance can include determining destination information for thepacket from the packet headers, identifying any policies (e.g., securitylists) configured for the VNIC associated with the source computeinstance, determining a next hop for the packet, performing any packetencapsulation/decapsulation functions as needed, and thenforwarding/routing the packet to the next hop with the goal offacilitating communication of the packet to its intended destination.When the destination compute instance is in the same subnet as thesource compute instance, the VNIC associated with the source computeinstance is configured to identify the VNIC associated with thedestination compute instance and forward the packet to that VNIC forprocessing. The VNIC associated with the destination compute instance isthen executed and forwards the packet to the destination computeinstance.

For a packet to be communicated from a compute instance in a subnet toan endpoint in a different subnet in the same VCN, the communication isfacilitated by the VNICs associated with the source and destinationcompute instances and the VCN VR. For example, if compute instance C1 inSubnet-1 in FIG. 1 wants to send a packet to compute instance D1 inSubnet-2, the packet is first processed by the VNIC associated withcompute instance C1. The VNIC associated with compute instance C1 isconfigured to route the packet to the VCN VR 105 using default route orport 10.0.0.1 of the VCN VR. VCN VR 105 is configured to route thepacket to Subnet-2 using port 10.1.0.1. The packet is then received andprocessed by the VNIC associated with D1 and the VNIC forwards thepacket to compute instance D1.

For a packet to be communicated from a compute instance in VCN 104 to anendpoint that is outside VCN 104, the communication is facilitated bythe VNIC associated with the source compute instance, VCN VR 105, andgateways associated with VCN 104. One or more types of gateways may beassociated with VCN 104. A gateway is an interface between a VCN andanother endpoint, where another endpoint is outside the VCN. A gatewayis a Layer-3/IP layer concept and enables a VCN to communicate withendpoints outside the VCN. A gateway thus facilitates traffic flowbetween a VCN and other VCNs or networks. Various different types ofgateways may be configured for a VCN to facilitate different types ofcommunications with different types of endpoints. Depending upon thegateway, the communications may be over public networks (e.g., theInternet) or over private networks. Various communication protocols maybe used for these communications.

For example, compute instance C1 may want to communicate with anendpoint outside VCN 104. The packet may be first processed by the VNICassociated with source compute instance C1. The VNIC processingdetermines that the destination for the packet is outside the Subnet-1of C1. The VNIC associated with C1 may forward the packet to VCN VR 105for VCN 104. VCN VR 105 then processes the packet and as part of theprocessing, based upon the destination for the packet, determines aparticular gateway associated with VCN 104 as the next hop for thepacket. VCN VR 105 may then forward the packet to the particularidentified gateway. For example, if the destination is an endpointwithin the customer's on-premise network, then the packet may beforwarded by VCN VR 105 to Dynamic Routing Gateway (DRG) gateway 122configured for VCN 104. The packet may then be forwarded from thegateway to a next hop to facilitate communication of the packet to itfinal intended destination.

Various different types of gateways may be configured for a VCN.Examples of gateways that may be configured for a VCN are depicted inFIG. 1 and described below. Examples of gateways associated with a VCNare also depicted in FIGS. 18, 19, 20, and 21 (for example, gatewaysreferenced by reference numbers 1834, 1836, 1838, 1934, 1936, 1938,2034, 2036, 2038, 2134, 2136, and 2138) and described below. As shown inthe embodiment depicted in FIG. 1 , a Dynamic Routing Gateway (DRG) 122may be added to or be associated with customer VCN 104 and provides apath for private network traffic communication between customer VCN 104and another endpoint, where the another endpoint can be the customer'son-premise network 116, a VCN 108 in a different region of CSPI 101, orother remote cloud networks 118 not hosted by CSPI 101. Customeron-premise network 116 may be a customer network or a customer datacenter built using the customer's resources. Access to customeron-premise network 116 is generally very restricted. For a customer thathas both a customer on-premise network 116 and one or more VCNs 104deployed or hosted in the cloud by CSPI 101, the customer may want theiron-premise network 116 and their cloud based VCN 104 to be able tocommunicate with each other. This enables a customer to build anextended hybrid environment encompassing the customer's VCN 104 hostedby CSPI 101 and their on-premises network 116. DRG 122 enables thiscommunication. To enable such communications, a communication channel124 is set up where one endpoint of the channel is in customeron-premise network 116 and the other endpoint is in CSPI 101 andconnected to customer VCN 104. Communication channel 124 can be overpublic communication networks such as the Internet or privatecommunication networks. Various different communication protocols may beused such as IPsec VPN technology over a public communication networksuch as the Internet, Oracle's FastConnect technology that uses aprivate network instead of a public network, and others. The device orequipment in customer on-premise network 116 that forms one end pointfor communication channel 124 is referred to as the customer premiseequipment (CPE), such as CPE 126 depicted in FIG. 1 . On the CSPI 101side, the endpoint may be a host machine executing DRG 122.

In certain embodiments, a Remote Peering Connection (RPC) can be addedto a DRG, which allows a customer to peer one VCN with another VCN in adifferent region. Using such an RPC, customer VCN 104 can use DRG 122 toconnect with a VCN 108 in another region. DRG 122 may also be used tocommunicate with other remote cloud networks 118, not hosted by CSPI 101such as a Microsoft Azure cloud, Amazon AWS cloud, and others.

As shown in FIG. 1 , an Internet Gateway (IGW) 120 may be configured forcustomer VCN 104 the enables a compute instance on VCN 104 tocommunicate with public endpoints 114 accessible over a public networksuch as the Internet. IGW 120 is a gateway that connects a VCN to apublic network such as the Internet. IGW 120 enables a public subnet(where the resources in the public subnet have public overlay IPaddresses) within a VCN, such as VCN 104, direct access to publicendpoints 112 on a public network 114 such as the Internet. Using IGW120, connections can be initiated from a subnet within VCN 104 or fromthe Internet.

A Network Address Translation (NAT) gateway 128 can be configured forcustomer's VCN 104 and enables cloud resources in the customer's VCN,which do not have dedicated public overlay IP addresses, access to theInternet and it does so without exposing those resources to directincoming Internet connections (e.g., L4-L7 connections). This enables aprivate subnet within a VCN, such as private Subnet-1 in VCN 104, withprivate access to public endpoints on the Internet. In NAT gateways,connections can be initiated only from the private subnet to the publicInternet and not from the Internet to the private subnet.

In certain embodiments, a Service Gateway (SGW) 126 can be configuredfor customer VCN 104 and provides a path for private network trafficbetween VCN 104 and supported services endpoints in a service network110. In certain embodiments, service network 110 may be provided by theCSP and may provide various services. An example of such a servicenetwork is Oracle's Services Network, which provides various servicesthat can be used by customers. For example, a compute instance (e.g., adatabase system) in a private subnet of customer VCN 104 can back updata to a service endpoint (e.g., Object Storage) without needing publicIP addresses or access to the Internet. In certain embodiments, a VCNcan have only one SGW, and connections can only be initiated from asubnet within the VCN and not from service network 110. If a VCN ispeered with another, resources in the other VCN typically cannot accessthe SGW. Resources in on-premises networks that are connected to a VCNwith FastConnect or VPN Connect can also use the service gatewayconfigured for that VCN.

In certain implementations, SGW 126 uses the concept of a serviceClassless Inter-Domain Routing (CIDR) label, which is a string thatrepresents all the regional public IP address ranges for the service orgroup of services of interest. The customer uses the service CIDR labelwhen they configure the SGW and related route rules to control trafficto the service. The customer can optionally utilize it when configuringsecurity rules without needing to adjust them if the service's public IPaddresses change in the future.

A Local Peering Gateway (LPG) 132 is a gateway that can be added tocustomer VCN 104 and enables VCN 104 to peer with another VCN in thesame region. Peering means that the VCNs communicate using private IPaddresses, without the traffic traversing a public network such as theInternet or without routing the traffic through the customer'son-premises network 116. In preferred embodiments, a VCN has a separateLPG for each peering it establishes. Local Peering or VCN Peering is acommon practice used to establish network connectivity between differentapplications or infrastructure management functions.

Service providers, such as providers of services in service network 110,may provide access to services using different access models. Accordingto a public access model, services may be exposed as public endpointsthat are publicly accessible by compute instance in a customer VCN via apublic network such as the Internet and or may be privately accessiblevia SGW 126. According to a specific private access model, services aremade accessible as private IP endpoints in a private subnet in thecustomer's VCN. This is referred to as a Private Endpoint (PE) accessand enables a service provider to expose their service as an instance inthe customer's private network. A Private Endpoint resource represents aservice within the customer's VCN. Each PE manifests as a VNIC (referredto as a PE-VNIC, with one or more private IPs) in a subnet chosen by thecustomer in the customer's VCN. A PE thus provides a way to present aservice within a private customer VCN subnet using a VNIC. Since theendpoint is exposed as a VNIC, all the features associates with a VNICsuch as routing rules, security lists, etc., are now available for thePE VNIC.

A service provider can register their service to enable access through aPE. The provider can associate policies with the service that restrictsthe service's visibility to the customer tenancies. A provider canregister multiple services under a single virtual IP address (VIP),especially for multi-tenant services. There may be multiple such privateendpoints (in multiple VCNs) that represent the same service.

Compute instances in the private subnet can then use the PE VNIC'sprivate IP address or the service DNS name to access the service.Compute instances in the customer VCN can access the service by sendingtraffic to the private IP address of the PE in the customer VCN. APrivate Access Gateway (PAGW) 130 is a gateway resource that can beattached to a service provider VCN (e.g., a VCN in service network 110)that acts as an ingress/egress point for all traffic from/to customersubnet private endpoints. PAGW 130 enables a provider to scale thenumber of PE connections without utilizing its internal IP addressresources. A provider needs only configure one PAGW for any number ofservices registered in a single VCN. Providers can represent a serviceas a private endpoint in multiple VCNs of one or more customers. Fromthe customer's perspective, the PE VNIC, which, instead of beingattached to a customer's instance, appears attached to the service withwhich the customer wishes to interact. The traffic destined to theprivate endpoint is routed via PAGW 130 to the service. These arereferred to as customer-to-service private connections (C2Sconnections).

The PE concept can also be used to extend the private access for theservice to customer's on-premises networks and data centers, by allowingthe traffic to flow through FastConnect/IPsec links and the privateendpoint in the customer VCN. Private access for the service can also beextended to the customer's peered VCNs, by allowing the traffic to flowbetween LPG 132 and the PE in the customer's VCN.

A customer can control routing in a VCN at the subnet level, so thecustomer can specify which subnets in the customer's VCN, such as VCN104, use each gateway. A VCN's route tables are used to decide iftraffic is allowed out of a VCN through a particular gateway. Forexample, in a particular instance, a route table for a public subnetwithin customer VCN 104 may send non-local traffic through IGW 120. Theroute table for a private subnet within the same customer VCN 104 maysend traffic destined for CSP services through SGW 126. All remainingtraffic may be sent via the NAT gateway 128. Route tables only controltraffic going out of a VCN.

Security lists associated with a VCN are used to control traffic thatcomes into a VCN via a gateway via inbound connections. All resources ina subnet use the same route table and security lists. Security lists maybe used to control specific types of traffic allowed in and out ofinstances in a subnet of a VCN. Security list rules may comprise ingress(inbound) and egress (outbound) rules. For example, an ingress rule mayspecify an allowed source address range, while an egress rule mayspecify an allowed destination address range. Security rules may specifya particular protocol (e.g., TCP, ICMP), a particular port (e.g., 22 forSSH, 3389 for Windows RDP), etc. In certain implementations, aninstance's operating system may enforce its own firewall rules that arealigned with the security list rules. Rules may be stateful (e.g., aconnection is tracked, and the response is automatically allowed withoutan explicit security list rule for the response traffic) or stateless.

Access from a customer VCN (i.e., by a resource or compute instancedeployed on VCN 104) can be categorized as public access, privateaccess, or dedicated access. Public access refers to an access modelwhere a public IP address or a NAT is used to access a public endpoint.Private access enables customer workloads in VCN 104 with private IPaddresses (e.g., resources in a private subnet) to access serviceswithout traversing a public network such as the Internet. In certainembodiments, CSPI 101 enables customer VCN workloads with private IPaddresses to access the (public service endpoints of) services using aservice gateway. A service gateway thus offers a private access model byestablishing a virtual link between the customer's VCN and the service'spublic endpoint residing outside the customer's private network.

Additionally, CSPI may offer dedicated public access using technologiessuch as FastConnect public peering where customer on-premises instancescan access one or more services in a customer VCN using a FastConnectconnection and without traversing a public network such as the Internet.CSPI also may also offer dedicated private access using FastConnectprivate peering where customer on-premises instances with private IPaddresses can access the customer's VCN workloads using a FastConnectconnection. FastConnect is a network connectivity alternative to usingthe public Internet to connect a customer's on-premise network to CSPIand its services. FastConnect provides an easy, elastic, and economicalway to create a dedicated and private connection with higher bandwidthoptions and a more reliable and consistent networking experience whencompared to Internet-based connections.

FIG. 1 and the accompanying description above describes variousvirtualized components in an example virtual network. As describedabove, the virtual network is built on the underlying physical orsubstrate network. FIG. 2 depicts a simplified architectural diagram ofthe physical components in the physical network within CSPI 200 thatprovide the underlay for the virtual network according to certainembodiments. As shown, CSPI 200 provides a distributed environmentcomprising components and resources (e.g., compute, memory, andnetworking resources) provided by a cloud service provider (CSP). Thesecomponents and resources are used to provide cloud services (e.g., IaaSservices) to subscribing customers, i.e., customers that have subscribedto one or more services provided by the CSP. Based upon the servicessubscribed to by a customer, a subset of resources (e.g., compute,memory, and networking resources) of CSPI 200 are provisioned for thecustomer. Customers can then build their own cloud-based (i.e.,CSPI-hosted) customizable and private virtual networks using physicalcompute, memory, and networking resources provided by CSPI 200. Aspreviously indicated, these customer networks are referred to as virtualcloud networks (VCNs). A customer can deploy one or more customerresources, such as compute instances, on these customer VCNs. Computeinstances can be in the form of virtual machines, bare metal instances,and the like. CSPI 200 provides infrastructure and a set ofcomplementary cloud services that enable customers to build and run awide range of applications and services in a highly available hostedenvironment.

In the example embodiment depicted in FIG. 2 , the physical componentsof CSPI 200 include one or more physical host machines or physicalservers (e.g., 202, 206, 208), network virtualization devices (NVDs)(e.g., 210, 212), top-of-rack (TOR) switches (e.g., 214, 216), and aphysical network (e.g., 218), and switches in physical network 218. Thephysical host machines or servers may host and execute various computeinstances that participate in one or more subnets of a VCN. The computeinstances may include virtual machine instances, and bare metalinstances. For example, the various compute instances depicted in FIG. 1may be hosted by the physical host machines depicted in FIG. 2 . Thevirtual machine compute instances in a VCN may be executed by one hostmachine or by multiple different host machines. The physical hostmachines may also host virtual host machines, container-based hosts orfunctions, and the like. The VNICs and VCN VR depicted in FIG. 1 may beexecuted by the NVDs depicted in FIG. 2 . The gateways depicted in FIG.1 may be executed by the host machines and/or by the NVDs depicted inFIG. 2 .

The host machines or servers may execute a hypervisor (also referred toas a virtual machine monitor or VMM) that creates and enables avirtualized environment on the host machines. The virtualization orvirtualized environment facilitates cloud-based computing. One or morecompute instances may be created, executed, and managed on a hostmachine by a hypervisor on that host machine. The hypervisor on a hostmachine enables the physical computing resources of the host machine(e.g., compute, memory, and networking resources) to be shared betweenthe various compute instances executed by the host machine.

For example, as depicted in FIG. 2 , host machines 202 and 208 executehypervisors 260 and 266, respectively. These hypervisors may beimplemented using software, firmware, or hardware, or combinationsthereof. Typically, a hypervisor is a process or a software layer thatsits on top of the host machine's operating system (OS), which in turnexecutes on the hardware processors of the host machine. The hypervisorprovides a virtualized environment by enabling the physical computingresources (e.g., processing resources such as processors/cores, memoryresources, networking resources) of the host machine to be shared amongthe various virtual machine compute instances executed by the hostmachine. For example, in FIG. 2 , hypervisor 260 may sit on top of theOS of host machine 202 and enables the computing resources (e.g.,processing, memory, and networking resources) of host machine 202 to beshared between compute instances (e.g., virtual machines) executed byhost machine 202. A virtual machine can have its own operating system(referred to as a guest operating system), which may be the same as ordifferent from the OS of the host machine. The operating system of avirtual machine executed by a host machine may be the same as ordifferent from the operating system of another virtual machine executedby the same host machine. A hypervisor thus enables multiple operatingsystems to be executed alongside each other while sharing the samecomputing resources of the host machine. The host machines depicted inFIG. 2 may have the same or different types of hypervisors.

A compute instance can be a virtual machine instance or a bare metalinstance. In FIG. 2 , compute instances 268 on host machine 202 and 274on host machine 208 are examples of virtual machine instances. Hostmachine 206 is an example of a bare metal instance that is provided to acustomer.

In certain instances, an entire host machine may be provisioned to asingle customer, and all of the one or more compute instances (eithervirtual machines or bare metal instance) hosted by that host machinebelong to that same customer. In other instances, a host machine may beshared between multiple customers (i.e., multiple tenants). In such amulti-tenancy scenario, a host machine may host virtual machine computeinstances belonging to different customers. These compute instances maybe members of different VCNs of different customers. In certainembodiments, a bare metal compute instance is hosted by a bare metalserver without a hypervisor. When a bare metal compute instance isprovisioned, a single customer or tenant maintains control of thephysical CPU, memory, and network interfaces of the host machine hostingthe bare metal instance and the host machine is not shared with othercustomers or tenants.

As previously described, each compute instance that is part of a VCN isassociated with a VNIC that enables the compute instance to become amember of a subnet of the VCN. The VNIC associated with a computeinstance facilitates the communication of packets or frames to and fromthe compute instance. A VNIC is associated with a compute instance whenthe compute instance is created. In certain embodiments, for a computeinstance executed by a host machine, the VNIC associated with thatcompute instance is executed by an NVD connected to the host machine.For example, in FIG. 2 , host machine 202 executes a virtual machinecompute instance 268 that is associated with VNIC 276, and VNIC 276 isexecuted by NVD 210 connected to host machine 202. As another example,bare metal instance 272 hosted by host machine 206 is associated withVNIC 280 that is executed by NVD 212 connected to host machine 206. Asyet another example, VNIC 284 is associated with compute instance 274executed by host machine 208, and VNIC 284 is executed by NVD 212connected to host machine 208.

For compute instances hosted by a host machine, an NVD connected to thathost machine also executes VCN VRs corresponding to VCNs of which thecompute instances are members. For example, in the embodiment depictedin FIG. 2 , NVD 210 executes VCN VR 277 corresponding to the VCN ofwhich compute instance 268 is a member. NVD 212 may also execute one ormore VCN VRs 283 corresponding to VCNs corresponding to the computeinstances hosted by host machines 206 and 208.

A host machine may include one or more network interface cards (NIC)that enable the host machine to be connected to other devices. A NIC ona host machine may provide one or more ports (or interfaces) that enablethe host machine to be communicatively connected to another device. Forexample, a host machine may be connected to an NVD using one or moreports (or interfaces) provided on the host machine and on the NVD. Ahost machine may also be connected to other devices such as another hostmachine.

For example, in FIG. 2 , host machine 202 is connected to NVD 210 usinglink 220 that extends between a port 234 provided by a NIC 232 of hostmachine 202 and between a port 236 of NVD 210. Host machine 206 isconnected to NVD 212 using link 224 that extends between a port 246provided by a NIC 244 of host machine 206 and between a port 248 of NVD212. Host machine 208 is connected to NVD 212 using link 226 thatextends between a port 252 provided by a NIC 250 of host machine 208 andbetween a port 254 of NVD 212.

The NVDs are in turn connected via communication links totop-of-the-rack (TOR) switches, which are connected to physical network218 (also referred to as the switch fabric). In certain embodiments, thelinks between a host machine and an NVD, and between an NVD and a TORswitch are Ethernet links. For example, in FIG. 2 , NVDs 210 and 212 areconnected to TOR switches 214 and 216, respectively, using links 228 and230. In certain embodiments, the links 220, 224, 226, 228, and 230 areEthernet links. The collection of host machines and NVDs that areconnected to a TOR is sometimes referred to as a rack.

Physical network 218 provides a communication fabric that enables TORswitches to communicate with each other. Physical network 218 can be amulti-tiered network. In certain implementations, physical network 218is a multi-tiered Clos network of switches, with TOR switches 214 and216 representing the leaf level nodes of the multi-tiered and multi-nodephysical switching network 218. Different Clos network configurationsare possible including but not limited to a 2-tier network, a 3-tiernetwork, a 4-tier network, a 5-tier network, and in general a “n”-tierednetwork. An example of a Clos network is depicted in FIG. 5 anddescribed below.

Various different connection configurations are possible between hostmachines and NVDs such as one-to-one configuration, many-to-oneconfiguration, one-to-many configuration, and others. In a one-to-oneconfiguration implementation, each host machine is connected to its ownseparate NVD. For example, in FIG. 2 , host machine 202 is connected toNVD 210 via NIC 232 of host machine 202. In a many-to-one configuration,multiple host machines are connected to one NVD. For example, in FIG. 2, host machines 206 and 208 are connected to the same NVD 212 via NICs244 and 250, respectively.

In a one-to-many configuration, one host machine is connected tomultiple NVDs. FIG. 3 shows an example within CSPI 300 where a hostmachine is connected to multiple NVDs. As shown in FIG. 3 , host machine302 comprises a network interface card (NIC) 304 that includes multipleports 306 and 308. Host machine 300 is connected to a first NVD 310 viaport 306 and link 320 and connected to a second NVD 312 via port 308 andlink 322. Ports 306 and 308 may be Ethernet ports and the links 320 and322 between host machine 302 and NVDs 310 and 312 may be Ethernet links.NVD 310 is in turn connected to a first TOR switch 314 and NVD 312 isconnected to a second TOR switch 316. The links between NVDs 310 and312, and TOR switches 314 and 316 may be Ethernet links. TOR switches314 and 316 represent the Tier-0 switching devices in multi-tieredphysical network 318.

The arrangement depicted in FIG. 3 provides two separate physicalnetwork paths to and from physical switch network 318 to host machine302: a first path traversing TOR switch 314 to NVD 310 to host machine302, and a second path traversing TOR switch 316 to NVD 312 to hostmachine 302. The separate paths provide for enhanced availability(referred to as high availability) of host machine 302. If there areproblems in one of the paths (e.g., a link in one of the paths goesdown) or devices (e.g., a particular NVD is not functioning), then theother path may be used for communications to/from host machine 302.

In the configuration depicted in FIG. 3 , the host machine is connectedto two different NVDs using two different ports provided by a NIC of thehost machine. In other embodiments, a host machine may include multipleNICs that enable connectivity of the host machine to multiple NVDs.

Referring back to FIG. 2 , an NVD is a physical device or component thatperforms one or more network and/or storage virtualization functions. AnNVD may be any device with one or more processing units (e.g., CPUs,Network Processing Units (NPUs), FPGAs, packet processing pipelines,etc.), memory including cache, and ports. The various virtualizationfunctions may be performed by software/firmware executed by the one ormore processing units of the NVD.

An NVD may be implemented in various different forms. For example, incertain embodiments, an NVD is implemented as an interface card referredto as a smartNIC or an intelligent NIC with an embedded processoronboard. A smartNIC is a separate device from the NICs on the hostmachines. In FIG. 2 , the NVDs 210 and 212 may be implemented assmartNICs that are connected to host machines 202, and host machines 206and 208, respectively.

A smartNIC is however just one example of an NVD implementation. Variousother implementations are possible. For example, in some otherimplementations, an NVD or one or more functions performed by the NVDmay be incorporated into or performed by one or more host machines, oneor more TOR switches, and other components of CSPI 200. For example, anNVD may be embodied in a host machine where the functions performed byan NVD are performed by the host machine. As another example, an NVD maybe part of a TOR switch, or a TOR switch may be configured to performfunctions performed by an NVD that enables the TOR switch to performvarious complex packet transformations that are used for a public cloud.A TOR that performs the functions of an NVD is sometimes referred to asa smart TOR. In yet other implementations, where virtual machines (VMs)instances, but not bare metal (BM) instances, are offered to customers,functions performed by an NVD may be implemented inside a hypervisor ofthe host machine. In some other implementations, some of the functionsof the NVD may be offloaded to a centralized service running on a fleetof host machines.

In certain embodiments, such as when implemented as a smartNIC as shownin FIG. 2 , an NVD may comprise multiple physical ports that enable itto be connected to one or more host machines and to one or more TORswitches. A port on an NVD can be classified as a host-facing port (alsoreferred to as a “south port”) or a network-facing or TOR-facing port(also referred to as a “north port”). A host-facing port of an NVD is aport that is used to connect the NVD to a host machine. Examples ofhost-facing ports in FIG. 2 include port 236 on NVD 210, and ports 248and 254 on NVD 212. A network-facing port of an NVD is a port that isused to connect the NVD to a TOR switch. Examples of network-facingports in FIG. 2 include port 256 on NVD 210, and port 258 on NVD 212. Asshown in FIG. 2 , NVD 210 is connected to TOR switch 214 using link 228that extends from port 256 of NVD 210 to the TOR switch 214. Likewise,NVD 212 is connected to TOR switch 216 using link 230 that extends fromport 258 of NVD 212 to the TOR switch 216.

An NVD receives packets and frames from a host machine (e.g., packetsand frames generated by a compute instance hosted by the host machine)via a host-facing port and, after performing the necessary packetprocessing, may forward the packets and frames to a TOR switch via anetwork-facing port of the NVD. An NVD may receive packets and framesfrom a TOR switch via a network-facing port of the NVD and, afterperforming the necessary packet processing, may forward the packets andframes to a host machine via a host-facing port of the NVD.

In certain embodiments, there may be multiple ports and associated linksbetween an NVD and a TOR switch. These ports and links may be aggregatedto form a link aggregator group of multiple ports or links (referred toas a LAG). Link aggregation allows multiple physical links between twoendpoints (e.g., between an NVD and a TOR switch) to be treated as asingle logical link. All the physical links in a given LAG may operatein full-duplex mode at the same speed. LAGs help increase the bandwidthand reliability of the connection between two endpoints. If one of thephysical links in the LAG goes down, traffic is dynamically andtransparently reassigned to one of the other physical links in the LAG.The aggregated physical links deliver higher bandwidth than eachindividual link. The multiple ports associated with a LAG are treated asa single logical port. Traffic can be load-balanced across the multiplephysical links of a LAG. One or more LAGs may be configured between twoendpoints. The two endpoints may be between an NVD and a TOR switch,between a host machine and an NVD, and the like.

An NVD implements or performs network virtualization functions. Thesefunctions are performed by software/firmware executed by the NVD.Examples of network virtualization functions include without limitation:packet encapsulation and de-capsulation functions; functions forcreating a VCN network; functions for implementing network policies suchas VCN security list (firewall) functionality; functions that facilitatethe routing and forwarding of packets to and from compute instances in aVCN; and the like. In certain embodiments, upon receiving a packet, anNVD is configured to execute a packet processing pipeline for processingthe packet and determining how the packet is to be forwarded or routed.As part of this packet processing pipeline, the NVD may execute one ormore virtual functions associated with the overlay network such asexecuting VNICs associated with compute instances in the VCN, executinga Virtual Router (VR) associated with the VCN, the encapsulation anddecapsulation of packets to facilitate forwarding or routing in thevirtual network, execution of certain gateways (e.g., the Local PeeringGateway), the implementation of Security Lists, Network Security Groups,network address translation (NAT) functionality (e.g., the translationof Public IP to Private IP on a host by host basis), throttlingfunctions, and other functions.

In certain embodiments, the packet processing data path in an NVD maycomprise multiple packet pipelines, each composed of a series of packettransformation stages. In certain implementations, upon receiving apacket, the packet is parsed and classified to a single pipeline. Thepacket is then processed in a linear fashion, one stage after another,until the packet is either dropped or sent out over an interface of theNVD. These stages provide basic functional packet processing buildingblocks (e.g., validating headers, enforcing throttle, inserting newLayer-2 headers, enforcing L4 firewall, VCN encapsulation/decapsulation,etc.) so that new pipelines can be constructed by composing existingstages, and new functionality can be added by creating new stages andinserting them into existing pipelines.

An NVD may perform both control plane and data plane functionscorresponding to a control plane and a data plane of a VCN. Examples ofa VCN Control Plane are also depicted in FIGS. 18, 19, 20, and 21 (seereferences 1816, 1916, 2016, and 2116) and described below. Examples ofa VCN Data Plane are depicted in FIGS. 18, 19, 20, and 21 (seereferences 1818, 1918, 2018, and 2118) and described below. The controlplane functions include functions used for configuring a network (e.g.,setting up routes and route tables, configuring VNICs, etc.) thatcontrols how data is to be forwarded. In certain embodiments, a VCNControl Plane is provided that computes all the overlay-to-substratemappings centrally and publishes them to the NVDs and to the virtualnetwork edge devices such as various gateways such as the DRG, the SGW,the IGW, etc. Firewall rules may also be published using the samemechanism. In certain embodiments, an NVD only gets the mappings thatare relevant for that NVD. The data plane functions include functionsfor the actual routing/forwarding of a packet based upon configurationset up using control plane. A VCN data plane is implemented byencapsulating the customer's network packets before they traverse thesubstrate network. The encapsulation/decapsulation functionality isimplemented on the NVDs. In certain embodiments, an NVD is configured tointercept all network packets in and out of host machines and performnetwork virtualization functions.

As indicated above, an NVD executes various virtualization functionsincluding VNICs and VCN VRs. An NVD may execute VNICs associated withthe compute instances hosted by one or more host machines connected tothe VNIC. For example, as depicted in FIG. 2 , NVD 210 executes thefunctionality for VNIC 276 that is associated with compute instance 268hosted by host machine 202 connected to NVD 210. As another example, NVD212 executes VNIC 280 that is associated with bare metal computeinstance 272 hosted by host machine 206 and executes VNIC 284 that isassociated with compute instance 274 hosted by host machine 208. A hostmachine may host compute instances belonging to different VCNs, whichbelong to different customers, and the NVD connected to the host machinemay execute the VNICs (i.e., execute VNICs-relate functionality)corresponding to the compute instances.

An NVD also executes VCN Virtual Routers corresponding to the VCNs ofthe compute instances. For example, in the embodiment depicted in FIG. 2, NVD 210 executes VCN VR 277 corresponding to the VCN to which computeinstance 268 belongs. NVD 212 executes one or more VCN VRs 283corresponding to one or more VCNs to which compute instances hosted byhost machines 206 and 208 belong. In certain embodiments, the VCN VRcorresponding to that VCN is executed by all the NVDs connected to hostmachines that host at least one compute instance belonging to that VCN.If a host machine hosts compute instances belonging to different VCNs,an NVD connected to that host machine may execute VCN VRs correspondingto those different VCNs.

In addition to VNICs and VCN VRs, an NVD may execute various software(e.g., daemons) and include one or more hardware components thatfacilitate the various network virtualization functions performed by theNVD. For purposes of simplicity, these various components are groupedtogether as “packet processing components” shown in FIG. 2 . Forexample, NVD 210 comprises packet processing components 286 and NVD 212comprises packet processing components 288. For example, the packetprocessing components for an NVD may include a packet processor that isconfigured to interact with the NVD's ports and hardware interfaces tomonitor all packets received by and communicated using the NVD and storenetwork information. The network information may, for example, includenetwork flow information identifying different network flows handled bythe NVD and per flow information (e.g., per flow statistics). In certainembodiments, network flows information may be stored on a per VNICbasis. The packet processor may perform packet-by-packet manipulationsas well as implement stateful NAT and L4 firewall (FW). As anotherexample, the packet processing components may include a replicationagent that is configured to replicate information stored by the NVD toone or more different replication target stores. As yet another example,the packet processing components may include a logging agent that isconfigured to perform logging functions for the NVD. The packetprocessing components may also include software for monitoring theperformance and health of the NVD and, also possibly of monitoring thestate and health of other components connected to the NVD.

FIG. 1 shows the components of an example virtual or overlay networkincluding a VCN, subnets within the VCN, compute instances deployed onsubnets, VNICs associated with the compute instances, a VR for a VCN,and a set of gateways configured for the VCN. The overlay componentsdepicted in FIG. 1 may be executed or hosted by one or more of thephysical components depicted in FIG. 2 . For example, the computeinstances in a VCN may be executed or hosted by one or more hostmachines depicted in FIG. 2 . For a compute instance hosted by a hostmachine, the VNIC associated with that compute instance is typicallyexecuted by an NVD connected to that host machine (i.e., the VNICfunctionality is provided by the NVD connected to that host machine).The VCN VR function for a VCN is executed by all the NVDs that areconnected to host machines hosting or executing the compute instancesthat are part of that VCN. The gateways associated with a VCN may beexecuted by one or more different types of NVDs. For example, certaingateways may be executed by smartNICs, while others may be executed byone or more host machines or other implementations of NVDs.

As described above, a compute instance in a customer VCN may communicatewith various different endpoints, where the endpoints can be within thesame subnet as the source compute instance, in a different subnet butwithin the same VCN as the source compute instance, or with an endpointthat is outside the VCN of the source compute instance. Thesecommunications are facilitated using VNICs associated with the computeinstances, the VCN VRs, and the gateways associated with the VCNs.

For communications between two compute instances on the same subnet in aVCN, the communication is facilitated using VNICs associated with thesource and destination compute instances. The source and destinationcompute instances may be hosted by the same host machine or by differenthost machines. A packet originating from a source compute instance maybe forwarded from a host machine hosting the source compute instance toan NVD connected to that host machine. On the NVD, the packet isprocessed using a packet processing pipeline, which can includeexecution of the VNIC associated with the source compute instance. Sincethe destination endpoint for the packet is within the same subnet,execution of the VNIC associated with the source compute instanceresults in the packet being forwarded to an NVD executing the VNICassociated with the destination compute instance, which then processesand forwards the packet to the destination compute instance. The VNICsassociated with the source and destination compute instances may beexecuted on the same NVD (e.g., when both the source and destinationcompute instances are hosted by the same host machine) or on differentNVDs (e.g., when the source and destination compute instances are hostedby different host machines connected to different NVDs). The VNICs mayuse routing/forwarding tables stored by the NVD to determine the nexthop for the packet.

For a packet to be communicated from a compute instance in a subnet toan endpoint in a different subnet in the same VCN, the packetoriginating from the source compute instance is communicated from thehost machine hosting the source compute instance to the NVD connected tothat host machine. On the NVD, the packet is processed using a packetprocessing pipeline, which can include execution of one or more VNICs,and the VR associated with the VCN. For example, as part of the packetprocessing pipeline, the NVD executes or invokes functionalitycorresponding to the VNIC (also referred to as executes the VNIC)associated with source compute instance. The functionality performed bythe VNIC may include looking at the VLAN tag on the packet. Since thepacket's destination is outside the subnet, the VCN VR functionality isnext invoked and executed by the NVD. The VCN VR then routes the packetto the NVD executing the VNIC associated with the destination computeinstance. The VNIC associated with the destination compute instance thenprocesses the packet and forwards the packet to the destination computeinstance. The VNICs associated with the source and destination computeinstances may be executed on the same NVD (e.g., when both the sourceand destination compute instances are hosted by the same host machine)or on different NVDs (e.g., when the source and destination computeinstances are hosted by different host machines connected to differentNVDs).

If the destination for the packet is outside the VCN of the sourcecompute instance, then the packet originating from the source computeinstance is communicated from the host machine hosting the sourcecompute instance to the NVD connected to that host machine. The NVDexecutes the VNIC associated with the source compute instance. Since thedestination end point of the packet is outside the VCN, the packet isthen processed by the VCN VR for that VCN. The NVD invokes the VCN VRfunctionality, which may result in the packet being forwarded to an NVDexecuting the appropriate gateway associated with the VCN. For example,if the destination is an endpoint within the customer's on-premisenetwork, then the packet may be forwarded by the VCN VR to the NVDexecuting the DRG gateway configured for the VCN. The VCN VR may beexecuted on the same NVD as the NVD executing the VNIC associated withthe source compute instance or by a different NVD. The gateway may beexecuted by an NVD, which may be a smartNIC, a host machine, or otherNVD implementation. The packet is then processed by the gateway andforwarded to a next hop that facilitates communication of the packet toits intended destination endpoint. For example, in the embodimentdepicted in FIG. 2 , a packet originating from compute instance 268 maybe communicated from host machine 202 to NVD 210 over link 220 (usingNIC 232). On NVD 210, VNIC 276 is invoked since it is the VNICassociated with source compute instance 268. VNIC 276 is configured toexamine the encapsulated information in the packet and determine a nexthop for forwarding the packet with the goal of facilitatingcommunication of the packet to its intended destination endpoint, andthen forward the packet to the determined next hop.

A compute instance deployed on a VCN can communicate with variousdifferent endpoints. These endpoints may include endpoints that arehosted by CSPI 200 and endpoints outside CSPI 200. Endpoints hosted byCSPI 200 may include instances in the same VCN or other VCNs, which maybe the customer's VCNs, or VCNs not belonging to the customer.Communications between endpoints hosted by CSPI 200 may be performedover physical network 218. A compute instance may also communicate withendpoints that are not hosted by CSPI 200 or are outside CSPI 200.Examples of these endpoints include endpoints within a customer'son-premise network or data center, or public endpoints accessible over apublic network such as the Internet. Communications with endpointsoutside CSPI 200 may be performed over public networks (e.g., theInternet) (not shown in FIG. 2 ) or private networks (not shown in FIG.2 ) using various communication protocols.

The architecture of CSPI 200 depicted in FIG. 2 is merely an example andis not intended to be limiting. Variations, alternatives, andmodifications are possible in alternative embodiments. For example, insome implementations, CSPI 200 may have more or fewer systems orcomponents than those shown in FIG. 2 , may combine two or more systems,or may have a different configuration or arrangement of systems. Thesystems, subsystems, and other components depicted in FIG. 2 may beimplemented in software (e.g., code, instructions, program) executed byone or more processing units (e.g., processors, cores) of the respectivesystems, using hardware, or combinations thereof. The software may bestored on a non-transitory storage medium (e.g., on a memory device).

FIG. 4 depicts connectivity between a host machine and an NVD forproviding I/O virtualization for supporting multitenancy according tocertain embodiments. As depicted in FIG. 4 , host machine 402 executes ahypervisor 404 that provides a virtualized environment. Host machine 402executes two virtual machine instances, VM1 406 belonging tocustomer/tenant #1 and VM2 408 belonging to customer/tenant #2. Hostmachine 402 comprises a physical NIC 410 that is connected to an NVD 412via link 414. Each of the compute instances is attached to a VNIC thatis executed by NVD 412. In the embodiment in FIG. 4 , VM1 406 isattached to VNIC-VM1 420 and VM2 408 is attached to VNIC-VM2 422.

As shown in FIG. 4 , NIC 410 comprises two logical NICs, logical NIC A416 and logical NIC B 418. Each virtual machine is attached to andconfigured to work with its own logical NIC. For example, VM1 406 isattached to logical NIC A 416 and VM2 408 is attached to logical NIC B418. Even though host machine 402 comprises only one physical NIC 410that is shared by the multiple tenants, due to the logical NICs, eachtenant's virtual machine believes they have their own host machine andNIC.

In certain embodiments, each logical NIC is assigned its own VLAN ID.Thus, a specific VLAN ID is assigned to logical NIC A 416 for Tenant #1and a separate VLAN ID is assigned to logical NIC B 418 for Tenant #2.When a packet is communicated from VM1 406, a tag assigned to Tenant #1is attached to the packet by the hypervisor and the packet is thencommunicated from host machine 402 to NVD 412 over link 414. In asimilar manner, when a packet is communicated from VM2 408, a tagassigned to Tenant #2 is attached to the packet by the hypervisor andthe packet is then communicated from host machine 402 to NVD 412 overlink 414. Accordingly, a packet 424 communicated from host machine 402to NVD 412 has an associated tag 426 that identifies a specific tenantand associated VM. On the NVD, for a packet 424 received from hostmachine 402, the tag 426 associated with the packet is used to determinewhether the packet is to be processed by VNIC-VM1 420 or by VNIC-VM2422. The packet is then processed by the corresponding VNIC. Theconfiguration depicted in FIG. 4 enables each tenant's compute instanceto believe that they own their own host machine and NIC. The setupdepicted in FIG. 4 provides for I/O virtualization for supportingmulti-tenancy.

FIG. 5 depicts a simplified block diagram of a physical network 500according to certain embodiments. The embodiment depicted in FIG. 5 isstructured as a Clos network. A Clos network is a particular type ofnetwork topology designed to provide connection redundancy whilemaintaining high bisection bandwidth and maximum resource utilization. AClos network is a type of non-blocking, multistage or multi-tieredswitching network, where the number of stages or tiers can be two,three, four, five, etc. The embodiment depicted in FIG. 5 is a 3-tierednetwork comprising tiers 1, 2, and 3. The TOR switches 504 representTier-0 switches in the Clos network. One or more NVDs are connected tothe TOR switches. Tier-0 switches are also referred to as edge devicesof the physical network. The Tier-0 switches are connected to Tier-1switches, which are also referred to as leaf switches. In the embodimentdepicted in FIG. 5 , a set of “n” Tier-0 TOR switches are connected to aset of “n” Tier-1 switches and together form a pod. Each Tier-0 switchin a pod is interconnected to all the Tier-1 switches in the pod, butthere is no connectivity of switches between pods. In certainimplementations, two pods are referred to as a block. Each block isserved by or connected to a set of “n” Tier-2 switches (sometimesreferred to as spine switches). There can be several blocks in thephysical network topology. The Tier-2 switches are in turn connected to“n” Tier-3 switches (sometimes referred to as super-spine switches).Communication of packets over physical network 500 is typicallyperformed using one or more Layer-3 communication protocols. Typically,all the layers of the physical network, except for the TORs layer aren-ways redundant thus allowing for high availability. Policies may bespecified for pods and blocks to control the visibility of switches toeach other in the physical network so as to enable scaling of thephysical network.

A feature of a Clos network is that the maximum hop count to reach fromone Tier-0 switch to another Tier-0 switch (or from an NVD connected toa Tier-0-switch to another NVD connected to a Tier-0 switch) is fixed.For example, in a 3-Tiered Clos network at most seven hops are neededfor a packet to reach from one NVD to another NVD, where the source andtarget NVDs are connected to the leaf tier of the Clos network.Likewise, in a 4-tiered Clos network, at most nine hops are needed for apacket to reach from one NVD to another NVD, where the source and targetNVDs are connected to the leaf tier of the Clos network. Thus, a Closnetwork architecture maintains consistent latency throughout thenetwork, which is important for communication within and between datacenters. A Clos topology scales horizontally and is cost effective. Thebandwidth/throughput capacity of the network can be easily increased byadding more switches at the various tiers (e.g., more leaf and spineswitches) and by increasing the number of links between the switches atadjacent tiers.

In certain embodiments, each resource within CSPI is assigned a uniqueidentifier called a Cloud Identifier (CID). This identifier is includedas part of the resource's information and can be used to manage theresource, for example, via a Console or through APIs. An example syntaxfor a CID is:

ocid1.<RESOURCE TYPE>.<REALM>.[REGION][.FUTURE USE].<UNIQUE ID>

where,ocid1: The literal string indicating the version of the CID;

-   -   resource type: The type of resource (for example, instance,        volume, VCN, subnet, user, group, and so on);        realm: The realm the resource is in Example values are “c1” for        the commercial realm, “c2” for the Government Cloud realm, or        “c3” for the Federal Government Cloud realm, etc. Each realm may        have its own domain name;        region: The region the resource is in. If the region is not        applicable to the resource, this part might be blank;        future use: Reserved for future use. unique ID: The unique        portion of the ID. The format may vary depending on the type of        resource or service.

Multi-Cloud Introduction

FIG. 6 depicts a simplified high-level diagram of a distributedenvironment 600 comprising multiple cloud environments provided bydifferent cloud service providers (CSPs) wherein the cloud environmentsinclude a particular cloud environment that provides specializedinfrastructure that enables one or more cloud services provided by thatparticular cloud environment to be used by customers of other cloudenvironments according to certain embodiments. As depicted in FIG. 6 ,various different cloud environments (also referred to as “clouds”) maybe provided by different cloud service providers (CSPs), each cloudenvironment or cloud offering one or more cloud services that can besubscribed to by one or more customers of that cloud environment. Theset of cloud services offered by a cloud environment provided by a CSPmay include one or more different types of cloud services including butnot restricted to Software-as-a-Service (SaaS) services,Infrastructure-as-a-Service (IaaS) services, Platform-as-a-Service(PaaS) services, Database-as-a-Service (DBaaS) services, and others.Examples of cloud environments provided by various CSPs include Oracle®Cloud Infrastructure (OCI) provided by Oracle Corporation, Microsoft®Azure provided by Microsoft Corporation, Google Cloud™ provided byGoogle LLC, Amazon Web Services (AWS®) provided by Amazon Corporation,and others. The cloud services offered by a particular cloud environmentmay be different from the set of cloud services offered by another cloudenvironment.

In a typical cloud environment, a CSP provides cloud service providerinfrastructure (CSPI) that is used to provide the one or more cloudservices that are offered by that cloud environment to its customers.The CSPI provided by a CSP may include various types of hardware andsoftware resources including compute resources, memory resources,networking resources, consoles for accessing the cloud services, andothers. A customer of a cloud environment provided by a CSP maysubscribe to one or more of the cloud services offered by that cloudenvironment. Various subscription models may be offered by the CSP toits customers. After a customer subscribes to a cloud service providedby a cloud environment, one or more users may be associated with thesubscribing customer and these users can use the cloud servicesubscribed to by the customer. In certain implementations, when acustomer subscribes to a cloud service provided by a particular cloudenvironment, a customer account or customer tenancy is created for thatcustomer. One or more users can then be associated with the customertenancy and these users can then use the services subscribed to by thecustomer under the customer tenancy. Information regarding the servicessubscribed to by a customer, the users associated with the customertenancy, etc., is usually stored within the cloud environment andassociated with the customer tenancy.

For example, three different cloud environments provided by threedifferent CSPs are depicted in FIG. 6 . These include a CloudEnvironment A (cloud A) 610 provided by a CSP A, a Cloud Environment B(cloud B) 640 provided by a CSP B, and a Cloud Environment C (cloud C)660 provided by a CSP C. Cloud A 610 includes infrastructure CSPI A 612provided by CSP A, and this infrastructure may be used to provide a setof services “Services A” 614 offered by cloud A 610. One or morecustomers (e.g., Cust A1 616-1, Cust A2 616-2) may subscribe to one ormore services from Services A 614 provided by cloud A 610. One or moreusers 618-1 may be associated with Customer A1 616-1 and can use theservices subscribed to by customer A1 616-1 in cloud A 610. In a similarmanner, one or more users 618-2 may be associated with customer A2 616-2and can use the services subscribed to by customer A2 616-2 in cloud A610. In various use cases, the services subscribed to by customer A1616-1 may be different from the services subscribed to by customer A2616-2.

As depicted in FIG. 6 , cloud B 640 includes infrastructure CSPI B 642provided by CSP B, and this infrastructure may be used to provide a setof services “Services B” 644 offered by cloud B 640. One or morecustomers (e.g., Cust_B1 646-1) may subscribe to one or more servicesfrom Services B 644. One or more users 648-1 may be associated withCustomer B1 646-1 and can use the services subscribed to by customer B1646-1 in cloud B 640.

As depicted in FIG. 6 , cloud C 660 includes infrastructure CSPI C 662provided by CSP C, and this infrastructure may be used to provide a setof services “Services C” 664 offered by cloud C 660. One or morecustomers (e.g., Cust_C1 666-1) may subscribe to one or more servicesfrom Services C 664. One or more users 668-1 may be associated withCustomer C1 666-1 and can use the services subscribed to by customer C1666-1 in cloud C 660. It is to be noted that Services A 614, Services B644, and Services C 664 can be different from each other.

In existing cloud implementations, each cloud provides a closedecosystem for its subscribing customers and associated users. As aresult, a customer of a cloud environment and its associated users arerestricted to using the services offered by the cloud that the customersubscribes to. For example, customer B1 646-1 and its users 648-1 arerestricted to using services B 644 provided by cloud B 640 and cannotuse their account in cloud B 640 to access services from a differentcloud environment, such as a services from services A 614 offered bycloud A 610 or a service from Services C 664 offered by cloud C 660. Theteachings described herein overcome this limitation. As described inthis disclosure, various techniques are described that enable a link tobe created between two cloud environments that enables a serviceprovided by a first cloud environment provided by a first CSP to be usedby a customer (and associated users) of a second different cloudenvironment provided by a second different CSP, using the customer'saccount in the second cloud environment.

For example, in the embodiment depicted in FIG. 6 , infrastructure CSPIA 612 provided by CSP A, in addition to other infrastructure 620,includes special infrastructure 622 (referred to as multi-cloud enablinginfrastructure 622 or MEI 622 or multi-cloud infrastructure 622) thatenables one or more services 614 offered by cloud A to be used bycustomers and associated users of other clouds, such as clouds B 640 andC 660, using the customer accounts in those other clouds. In certainimplementations, customers of clouds B and C do not have to openseparate accounts with cloud A to use one or more of services 614offered by cloud A 610. A customer B1 646-1 of cloud B 640 and anassociated user 648-1 can use their customer account or tenancy in cloudB 640 to use one or more services 614 provided by cloud A 610. Asanother example, a customer C1 666-1 of cloud C 660 and an associateduser 668-1 can use their customer account or tenancy in cloud C 660 touse one or more services 614 provided by cloud A 610.

In certain implementations, MEI 622 enables links to be created betweencloud A 610 and other clouds, where these links can be used by customersof the other clouds and their associated users to access and make use ofservices provided by cloud A 610. This is symbolically shown in FIG. 6as a link 670 created between cloud A 610 and cloud B 640, and a link672 created between cloud A 610 and cloud C 660. Via link 670, acustomer of cloud B 640 can access or use one or more services 614provided by cloud A 610. Likewise, via link 672, a customer of cloud C660 can access or use one or more services 614 provided by cloud A 610.

There are different ways in which MEI 612 may be implemented. In certainembodiments, MEI 612 may include components that enable links to beestablished with different clouds. For example, in FIG. 6 , MEI 622includes an infrastructure component 624 that is responsible forenabling link 670 with cloud B 640, and an infrastructure component 626for enabling link 672 with cloud C 660. In a similar manner, MEI 622 mayinclude other components that enable and facilitate links with otherclouds. In some implementations, a component of MEI 622 may alsofacilitate links with multiple different clouds.

There are several reasons why a customer of one cloud may want or desireto use a cloud service provided by a different cloud. Using FIG. 6 as anexample, there are multiple reasons why a customer B1 646-1 of cloud B640 may want to use a cloud service 614 provided by cloud A 610. In oneuse case scenario, this may happen because cloud A 610 offers a cloudservice with functionality that is not provided by cloud B 640. Asanother use case scenario, clouds A and B may offer a similar service,but the service provided by cloud A 610 may be better (e.g., morefeatures/functionality, faster, etc.) that the corresponding serviceoffered by cloud B 640. As yet another use case scenario, customer B1646-1 of cloud B 640 may want to use a cloud service provided by cloud A610 because the service is provided at a cheaper price point than bycloud B 640. In some cases, there may be geographical restrictions orother reasons why customer B1 646-1 of cloud B 640 might want to use acloud service provided by cloud A 610. For example, cloud A 610 mayoffer the desired service in a geographical area that is not serviced bycloud B 640, or the particular service is not provided by cloud B 640 ina geographical area in which the customer desires the service. Severalother use case scenarios are also possible as to why a customer of onecloud might want to use a service provided by a different cloud.

In certain embodiments, MEI 622 provides capabilities and performsfunctions for creating the link between cloud A 610 and another cloud,and via the link, enabling a user associated with a customer of theother cloud to, in a seamless manner, access and use, from the othercloud itself, a service provided by cloud A 610. For example, MEI 622enables a user 648-1 associated with customer B1 646-1 of cloud 640 toaccess a service from services A 614 provided by cloud A 610 in aseamless manner. In certain implementations, user interfaces (e.g., aconsole) may be provided that user 648-1 can access from within cloud B640 that enable the user to see a list of services 614 offered by cloudA 610 and to select a particular service that the user 648-1 desires toaccess. In response to the user selection, MEI 622 is responsible forperforming processing that establishes link 670 between clouds A and Bto enable access to the requested service. The processing for setting uplink 670 is performed substantially automatically by MEI 622. CustomerB1 646-1 or associated users 648-1 do not have worry about performingany system, networking, or other configuration changes that are neededto facilitate the creation, maintenance, and usage of link 670 betweenclouds A 610 and B 640. No burden is placed on the users or thecustomers in the creation of the link between the clouds. The link iscreated in a fast and efficient manner using the techniques described inthis disclosure.

MEI 622 may use various techniques to make the creation and use of thelink seamless to users and customers and thus provide for an enhanceduser experience. In certain implementations, MEI 622 causes the userinterfaces (e.g., graphical user interfaces GUIs, etc.) and processflows that a customer B1 and associated users 648-1 interact with, suchas for requesting a service from cloud A 610 and for accessing therequested service from cloud A 610, to be substantially similar to theinterfaces and process flows that the customer/user would experience incloud B 640. In this manner, the customer or user, who may be accustomedto the interfaces and process flows of cloud B 640, does not have tolearn new interfaces and process flows to access a service 614 fromcloud A 610. MEI 622 may present different interfaces and process flowsfor users of different cloud environments. For example, a first set ofuser interfaces and process flows that are substantially similar to theuser interfaces and flows of cloud B may be presented to a user fromcloud B 640, while a different set of user interfaces and process flowsthat are substantially similar to the user interfaces and flows of cloudC may be presented to a user accessing cloud A 610 from cloud C 660.This is done to simplify and consequently enhance a user's experiencefor accessing services 614 of cloud A 610 from other clouds.

As another example, each cloud environment typically includes anidentify management system that is configured to provide security forthe cloud environment. The identity management system is configured toprotect resources in the cloud environment, including resources providedby the CSP and resources of subscribing cloud customers that aredeployed in the cloud environment. Functions performed by the identitymanagement system include, for example, managing identity credentials(e.g., usernames, passwords, etc.) associated with the cloud'ssubscribing customers and associated users, using the identitycredentials to regulate users' access to cloud resources and servicesbased upon permission/access policies configured for the cloudenvironment, and other functions. Different clouds may use differentidentity management systems and associated techniques. For example, theidentity management system and associated procedures in cloud A 610 maybe completely different from the identity management system andassociated procedures in cloud B 640, which in turn may be completelydifferent from the identity management system and associated proceduresin cloud C 660. In certain implementations, in spite of thesedifferences in identity management systems and associated proceduresbetween different cloud environments, the techniques described hereinenable a user associated with a customer of a first cloud to access acloud service provided by a different cloud using the same identitycredentials associated with the customer and the user in the firstcloud.

For example, in the embodiment depicted in FIG. 6 , cloud B 640 providedby CSP B may include an identity management system that assigns orallocates identity credentials to its subscribing customers andassociated users, such as customer B1 646-1 and associated users 648-1.These identity credentials are associated with the tenancy created forcustomer B1 646-1 in cloud B 640. In certain implementations, MEI 622provided by cloud A 610 enables a user 648-1 associated with cloud Bcustomer B1 646-1 to access a service from services A 614 in cloud A 610using identity credentials associated with users 648-1 and customer B1646-1 in cloud B 640. This greatly enhances the user experience forusers 648-1 since they do not have to create new identity credentialsthat are specific to cloud A 610 just for the purpose of accessing aservice 614 in cloud A 610. The MEI 622 facilitates such access.

As an example, a customer B1 of cloud B 640 may select to use a service,such as a Database-as-a Service (DBaaS), from the set of services 614provided by cloud A 610. In response to such a selection, MEI 622 causesa link 670 to be automatically created between cloud A 610 and cloud B640 to enable users 648-1 associated with customer B1 646-1 to use theDBaaS service provided by cloud A 610. The automatic setup of link 670is facilitated by MEI 622. After link 670 has been set up, a user 648-1can use the DBaaS service in cloud A 610 via cloud B 640. As part ofusing this service, user 648-1 can, via cloud B 640 send a request tocloud A 610 to create a database resource. In response, CSPI A 612 maycreate the requested database in cloud A 610. In certainimplementations, the created database may be provisioned in a virtualnetwork (e.g., a virtual cloud network or VCN) created for customer B1in cloud A 610 and is accessible to user 648-1 via cloud B 640. User648-1 may then send, from cloud B 640, requests to cloud A 610 to usethe provisioned database. These requests may include, for example,requests to write data to the database, to update data stored in thedatabase, to delete data in the database, to delete the database, tocreate additional databases, and the like. In some use cases, theserequests may originate from a user 648-1 via cloud B 640 or from aservice 644 provided by cloud B 640. In this manner, MEI 622 provided bycloud A 610 enables a user associated with a customer of a differentcloud provided by a different CSP to seamlessly access a serviceprovided by cloud A 610.

Distributed environment 600 depicted in FIG. 6 is merely an example andis not intended to unduly limit the scope of claimed embodiments. Manyvariations, alternatives, and modifications are possible. For example,in alternative embodiments, distributed environment 600 may have more orfewer cloud environments. The cloud environments may also have more orfewer systems and components or may have a different configuration orarrangement of the systems and components. The systems and componentsdepicted in FIG. 6 may be implemented in software (e.g., code,instructions, program) executed by one or more processing units (e.g.,processors, cores) of the respective systems, using hardware, orcombinations thereof. The software may be stored on a non-transitorystorage medium (e.g., on a memory device).

Multi Cloud Control Plane (MCCP)

FIG. 7 depicts a high-level architecture of a Multi-Cloud Control Plane(MCCP) according to some embodiments. As shown in FIG. 7 , thehigh-level architecture 700 includes a first cloud environment providedby a first cloud services provider (e.g., OCI) 720 and a second cloudenvironment provided by a second cloud services provider 710 (i.e.,Azure). The first cloud environment 720 includes a first cloudinfrastructure 720A that provides users of the first cloud environment720 with a plurality of services. Additionally, the first cloudenvironment 720 includes a multi-cloud infrastructure 720B thatprovisions for capabilities to deliver services of the first cloudinfrastructure 720A (e.g., Oracle Cloud Infrastructure (OCI)) to usersof other cloud environment (e.g., the second cloud infrastructure 710A).The multi-cloud infrastructure 720B allows users to access services(e.g., Oracle PaaS services) on other clouds with a user experience asclose as possible to that of the native cloud environments of the users,while providing simple integration between the cloud environments.

The second cloud infrastructure 710A includes a second cloud portal 711,an active directory 712, a resource manager 713, a customer subscription715, a subscription of the first cloud provider 717. The second cloudportal 711 is a centralized access point where customers of the secondenvironment 710 can login and manage their cloud deployments andinstances. It is noted that the second cloud portal may provide optionsfor both monitoring and operating services provided by the second cloudinfrastructure. The active directory 712 is a service provided by thesecond cloud infrastructure 710A that that provides administrators withthe ability to manage end-user identities and access privileges. Itsservices may include core directory, access management, and identityprotection. The resource manager 713 is a deployment and managementservice of the second cloud infrastructure i.e., a management layer thatprovides users to perform operations (e.g., create, update, delete,etc.,) with respect to resources deployed in the customer subscription715. It is noted that the customer subscription may also be referred toas a virtual network (VNET) where customer applications are deployed andexecuted. The subscription of the first cloud provider 717 in the secondcloud infrastructure 710A includes an express route and a hub and spokeVNET that provision for network connections (e.g., from on-premiseslocations, from external cloud environments) to be established with thesecond cloud infrastructure 710A. It is noted that such connections maynot be routed through the public internet, thereby providing users withmore reliability, faster speeds, consistent latency, and highersecurity.

The first cloud infrastructure 720A includes a control plane 724, acustomer tenancy 726, and a multi-cloud infrastructure 720B. The controlplane 724 of the first cloud infrastructure 720A is a native controlplane of the first cloud environment that provides management andorchestration across the cloud environment. It is here whereconfiguration baselines are set, user and role access provisioned, andapplications reside so they can be executed with related services. Themulti-cloud infrastructure 720B includes a multi-cloud platform dataplane 722 and multi-cloud platform data plane 728. As stated previously,the multi-cloud infrastructure 720B provisions for users of other cloudenvironments (e.g., the second cloud environment 710) to access servicesprovided by the first cloud environment with a user experience as closeas possible to that of the native cloud environments of the users (e.g.,the second cloud environment 710), while providing simple integrationbetween the cloud environments.

The MCCP architecture of FIG. 7 further includes a multi-cloud console721 (different than the second cloud portal 711) that permits usersauthenticated in the second cloud infrastructure 710 to perform controlplane operations on resources of the first cloud infrastructure 720 thatare exposed via the multi-cloud infrastructure 720B. In someimplementations, as shown in FIG. 7 , all user 705 requests transmittedto the multi-cloud console 721 are directed to the multi-cloudinfrastructure included in the first cloud environment. It isappreciated that the user 705 can transmit requests (e.g., CRUDrequests) with respect to resources provided by the first cloudinfrastructure directly to the multi-cloud console 721. The multi-cloudconsole 721 is configured to process requests that have a syntax orformat similar to that as used locally in the second cloudinfrastructure. In other words, the multi-cloud console 721 has asimilar look-and-feel as well as uses terminology that is similar to thesecond cloud portal 711 included in the second cloud infrastructure710A. In some implementations, a link (e.g., a weblink) may be providedin the second cloud console 711 that directs users to the multi-cloudconsole 721.

The multi-cloud infrastructure 720B included in the first cloudinfrastructure 720A includes a plurality of microservices such as anauthority module 722A, a proxy module 722B, a platform services module722C, a cloud-link adaptor 722D, a pool of adaptors 722E includingadaptor 1, adaptor 2, adaptor 3, and adaptor 4, and a network linkadaptor 722F. The pool of adaptors 722E can include adaptors such as anExa-data cloud service adaptor, an autonomous database-shared adaptor,an autonomous database-dedicated adaptor, and a virtual machine databaseadaptor.

Each of the adaptors included in the pool of adaptors 722E isresponsible for exposing a set of unique underlying resources (providedby the first cloud infrastructure 720A) to users of other cloudenvironments (e.g., second cloud environment). Specifically, each of theadaptors in the pool of adaptors 722E maps to a particular product orresource offered by the first cloud infrastructure 720A. It is notedthat the actual resources are created by the native control plane 724 ofthe first cloud infrastructure. For instance, with respect to databaseas a service (DBaaS), the DBaaS control plane included in the controlplane 724 is configured to instantiate Exa-database resources in thecustomer tenancy 726 of the first cloud environment.

The incoming request received by the multi-cloud infrastructure 720B isprocessed by the authority module 722A for performing authentication andaccess control. Each request includes a token associated with theaccount of the user in the second cloud infrastructure. The authoritymodule extracts the token and validates the token in conjunction withthe active directory 712 (i.e., the identity provider system of thesecond cloud infrastructure 710A). Upon successful validation, theauthority module 722A may check roles (i.e., set of privileges)associated with the user. It is noted that a role may be associated withone or more tasks/operations that are permitted for the role. Accordingto one embodiment, the authority module 722A is responsible forauthenticating incoming requests to MCCP and authorizing if the user isallowed to perform the requested operation based on the roles associatedwith the token. In some implementations, the authority module 722A mayperform the authentication process described above by taking advantageof a custom authentication feature of a service platform (i.e., SPLATassociated with the first cloud infrastructure). SPLAT accepts anincoming request and forwards it to the authority module 722A, whichfurther parse the incoming request to determine an authorizationdecision and returns a success or failure message back to SPLAT. Onsuccess, the request is passed by SPLAT to the routing proxy 722B,whereas on failure, SPLAT returns an error response directly to thecaller.

The proxy module 722B (also referred to as a routing proxy module)included in the multi-cloud infrastructure 720B is a component thatreceives an incoming request from the multi-cloud console 721 and routesthe request to a particular adaptor included in the pool of adaptors722E. By one embodiment, the proxy module 722B accepts pre-authenticatedrequests from a service platform (i.e., SPLAT) of the first cloudinfrastructure and routes the requests to the appropriate adaptor basedon path information included in the incoming request. In someimplementations, the proxy module 722B extracts an identifier (from theincoming request) corresponding to a provider of the service and routesthe request to the appropriate adaptor in the pool of adaptors 722E.

The cloud-link adaptor 722D included in the multi-cloud infrastructure720B is responsible for handling lifecycle operations of resourcesprovided by the first cloud infrastructure. The cloud-link adaptor 722Dis configured to create a mapping (or a relationship created at asign-up process) between an active directory tenant of the second cloudinfrastructure (and its associated subscriptions) and a correspondingtenancy/account of the user in the first cloud infrastructure. In otherwords, the cloud-link adaptor 722D generates a mapping of a firstidentifier associated with the tenancy of the user in the first cloudinfrastructure to a second identifier associated with the account of theuser in the second cloud infrastructure.

In some implementations, the cloud-link adaptor 722D performstranslation between external cloud identifiers (e.g., second identifierassociated with the account of the user in the second cloudinfrastructure) and a first identifier (associated with the tenancy ofthe user in the first cloud infrastructure) to enable operations goingthrough the multi-cloud control plane 722 to map to the appropriateunderlying resource in the first cloud infrastructure. In someembodiments, the cloud-link adaptor generates a data object to store theabove-described mapping information. Additionally, the cloud-linkadaptor 722D also generates a resource-principal that is associated withthe data object. The resource-principal is assigned one or morepermissions based on the token (and associated roles thereof) includedin the request. Access to downstream services provided by the firstcloud infrastructure is achieved by the user from the second cloudinfrastructure based on the resource-principal. The cloud-link adaptor722D may store the data object and the associated resource-principal ina root compartment of a tenancy of the user in the first cloudinfrastructure. Alternatively, or additionally, the cloud-link adaptor722D may also locally persist the data object and the resource-principalon the platform services module 722C of the multi-cloud infrastructurefor seamless access by other adaptors included in the multi-cloudinfrastructure.

The network link module (also referred to as a network adaptor) 722F isresponsible for creating a network link between the customersubscription 715 (in the second cloud infrastructure) and thecorresponding customer tenancy/account (in the first cloudinfrastructure) 726. By some embodiments, the network link module 722Fobtains a token (from the platform services module 722C) and creates (1)a first peering relationship (in the first cloud environment) betweenthe multi-cloud platform data plane 728 and the customer tenancy 726,and (2) a second peering relationship (in the second cloud environment)between the customer subscription 715 and the subscription of the firstcloud services provider 717 included in the second cloud infrastructure.

The network link module 722F is also configured to establish networkconnectivity between the first cloud environment and the second cloudenvironment i.e., the network link module 722F can configure aninterconnect 719 to communicatively couple the two cloud environments.It is appreciated that upon forming the network link between the twocloud environments, applications that are executed in the customer'ssubscription (e.g., in a VNET of the second cloud infrastructure) areable to access resources e.g., Exa-database resource that is deployed inthe customer tenancy 726 of the first cloud infrastructure. Further, asshown in FIG. 7 , within the tenancy 726, there is provided afunctionality of telemetry. Such a functionality relates to maintaininglogs, metrics, and other performance parameters related to the resourcesdeployed in the customer tenancy and their respective usages. Accordingto some embodiments, MCCP mirrors the logs and metrics associated withdifferent resources in the first cloud environment and publishes themetrics, logs, events etc., for instance in a dashboard (e.g., in anapplication insights module included in the customer subscription 715 ofthe second cloud environment) for further processing.

By some embodiments, the platform services module 722C included inmulti-cloud infrastructure is configured to store credentials associatedwith services of the first cloud infrastructure provided to the secondcloud infrastructure. The platform services module 722C provides, forinstance, tokens/resource principals for the different adaptors includedin the pool of adaptors 722E so that the adaptors can communicate withnative control plane 724 of the first cloud infrastructure. By someembodiments, the platform services module 722C exposes APIs that arecalled by different adaptors to perform tasks such as:

-   -   Vending a minimally scoped access token (issued by the second        cloud infrastructure) to adaptors. For example, the network        adaptor 722F requires an access token to perform the        above-described network peering operations.    -   Providing a resource principal that adaptors will use to call        downstream services to create resources in customer tenancies of        the first cloud infrastructure.    -   Triggering replication of observability data (logs, metrics,        events) from the first cloud infrastructure to the second cloud        infrastructure.

As stated previously, the pool of adaptors includes a plurality ofadaptors, each of which is responsible for exposing a set of uniqueunderlying resources of the first cloud infrastructure to the users ofthe second cloud infrastructure i.e., each adaptor maps to a particularproduct or resource offered by the first cloud environment. Forinstance, the Exa-database adaptor acts as a proxy for the users of thesecond cloud infrastructure to create and utilize Exa-databaseresources. Exa-database is a pre-configured combination of hardware andsoftware that provides an infrastructure for executing databases. Bysome embodiments, Exa-database comprises a stack of resources: (a)Exadata infrastructure (i.e., hardware), (b) VM cloud cluster, (c)container databases, and (d) pluggable databases. According to someembodiments, the multi-cloud infrastructure provides the ability (forusers of the second cloud infrastructure) to analyze each of the levelsof stacked infrastructure. Moreover, the MCCP provides flexibility for auser to simply issue a create command (via the multi-cloud console 721)for a workflow, where after the MCCP performs automatic creation ofindividual resources at each level of the stack. It is appreciated thatalthough the pool of adaptors 722F as depicted in FIG. 7 includes fourdifferent adaptors, it is in no way limiting the scope of the MCCParchitecture 700. The MCCP architecture may include other adaptors, forexample, a dedicated adaptor directed for use by a specific cloudservice provider based on requirements of the cloud services provider.

FIGS. 8A and 8B depict exemplary flow diagrams for linking two useraccounts in different cloud environments, according to some embodiments.The two user accounts may correspond to a first user account (e.g.,tenancy) in a first cloud infrastructure and a second user account in asecond cloud infrastructure. FIG. 8A depicts the process of linking thetwo user accounts, wherein the tenancy of the user is initially createdin the first cloud infrastructure and then linked to the account of theuser in the second cloud infrastructure. FIG. 8B depicts the process oflinking the two user accounts, wherein the tenancy of the user in thefirst cloud infrastructure is already created i.e., the tenancy alreadyexists.

FIG. 8A depicts a data flow that is executed when a user representing acustomer, such as a system administrator makes a call from the secondcloud infrastructure to the multi-cloud infrastructure (included in thefirst cloud infrastructure) for signing up for services provided in thefirst cloud infrastructure. A special console (referred to herein as amulti-cloud console) may be provided for users of the second cloudinfrastructure to open accounts within the first cloud infrastructureand to link the account of the user in the first cloud infrastructure tothe account of the user in the second cloud infrastructure. It is notedthat linking the accounts in the first and second cloud infrastructures,enables the user to utilize (from the second cloud infrastructure), oneor more services provided by the first cloud infrastructure. In certainimplementations, the user signs up for the services using themulti-cloud console. In response to the sign-up, a URL may be sent tothe user that enables the user to log into the multi-cloud console. Themulti-cloud console exposes UIs and APIs that are similar to the UIs andAPIs of the second cloud infrastructure.

The multi-cloud console may provide various UIs (e.g., GUIs) thatprovide user-selectable options that enable a user of the second cloudinfrastructure to open an account in the first cloud infrastructure andto further link the user accounts in the first and second cloudinfrastructures. For example, multi-cloud console may provide a sign-upUI, which enables a user to create an account/tenancy in the first cloudinfrastructure and to link the user's account (in the first cloudinfrastructure) to the user's account in the second cloudinfrastructure. Once the processing triggered responsive to thesignup/link request is complete the user's accounts in the respectivecloud infrastructures are linked together. As part of the processing,the multi-cloud console enables a user (e.g., a system administrator) tolog into the second cloud infrastructure, and request: (a) creation ofan account for the user (in the first cloud infrastructure) and to linkthe user's accounts; or (b) for an account that the user already has inthe first cloud infrastructure, to request the user's first cloudinfrastructure account to be linked to the user's second cloudinfrastructure account.

Accordingly, in certain use cases, there are two possibilities: (a) theuser already has an existing account or tenancy in the first cloudinfrastructure and now, via the multi-cloud console sign-up UI, the userrequests a link to be created between the user's accounts (detailspertaining to this processing is described next with reference to FIG.8B), or (b) the user requests both the creation of a new account in thefirst cloud infrastructure and the linking of the newly created accountwith the user's account in the second cloud infrastructure. Detailspertaining to this processing is described next with reference to FIG.8A. It is appreciated that linking of the accounts enables a user to,via the second cloud, use resources in the first cloud. For example, viathe second cloud, a user can request a resource to be created orprovisioned in the first cloud, utilize and manage resources in thefirst cloud, delete resources in the first cloud, and the like.

As shown in FIG. 8A, in step 1, in response to a user's input providedto multi-cloud console (e.g., sign-up UI of the multi-cloud console)requesting a new account for the user to be created in the first cloudinfrastructure and linked to the user's account in the second cloudinfrastructure, a call is made by the multi-cloud console to accountsservices (in the first cloud infrastructure) to create a new account. Itis noted that the call includes a token that is generated by secondcloud infrastructure. The token generated by the second cloudinfrastructure and included in the call to the accounts services enablesthe account or tenancy created in the first cloud infrastructure to belinked to the user's account in the second cloud infrastructure.

At step 2, as part of the processing for setting up the new account forthe user, accounts service may make a call to the authority/proxy moduleincluded in the multi-cloud control plane (e.g., authority module 722Aincluded in the multi-cloud infrastructure of FIG. 7 ) to validate thetoken. The authority/proxy module validates the token (as describedpreviously with reference to FIG. 7 ) and further processing maycontinue only upon successful validation of the token. Upon successfulvalidation of the token, accounts service creates a new account for theuser in the first cloud infrastructure. As part of creating the newaccount, a native user may be created and associated with the newlycreated account. However, note that this native user's credentials arenot used. Rather, the user's identity in the second cloud infrastructureis used for managing the account and its resources (from the secondcloud infrastructure) in the first cloud infrastructure.

After the new account has been successfully created by accounts servicesin the first cloud infrastructure, at step 3, accounts services makes acall to the cloud-link adaptor (included in the multi-cloudinfrastructure) to create a link (also referred to as a cloud-link)between the user's account in the second cloud infrastructure and thenewly created account in the first cloud infrastructure. In certainimplementations, the cloud-link adaptor exposes APIs to account servicesand to multi-cloud console. These APIs may be called by account services(or by the multi-cloud console) to request linking of the accounts. Itis noted that in some implementations, there is no token included in thecall of step 3, since the call requesting the linkage is not made by theuser but is rather initiated by accounts services. In this case,cloud-link adaptor does not do another authentication that would requireanother token because it relies upon accounts services having alreadyperformed the necessary authentication for the user as part of theprocessing for setting up the account using the token received in step1.

In some implementations, the processing performed in step 3 by thecloud-link adaptor for linking the two accounts comprises:

-   -   (a) cloud-link adaptor creates a data object (also referred to        herein as a cloud-link resource object for storing metadata        information identifying the two accounts being linked. For        example, the data object stores metadata information including a        mapping of a first identifier associated with the tenancy (i.e.,        account) created in the first cloud infrastructure and a second        identifier associated with the account of the user with the        second cloud service provider.    -   (b) cloud-link adaptor creates a new compartment for storing and        containing resources on the first cloud infrastructure side that        the user can/would manage using the multi-cloud console. In some        implementations, the cloud-link resource object is created at        the root of the customer's account in the first cloud        infrastructure.    -   (c) cloud-link adaptor creates a new resource-principal        (referred to herein as a cloud-link resource principal) for a        resource that is desired to be used by the user of the second        cloud infrastructure.    -   (d) cloud-link adaptor may perform one or more federation setups        that facilitate linking of a domain in the first cloud        infrastructure to an active directory (e.g., Active Directory        712 of the second cloud infrastructure as shown in FIG. 7 ). The        process of federating accounts of the first cloud infrastructure        and the second cloud infrastructure allows users/groups of users        in the second cloud infrastructure to be authenticated in first        cloud infrastructure, and users/groups from the first cloud        infrastructure to be authenticated into the second cloud        infrastructure.

In certain implementations, permissions are associated with thecloud-link resource principal based upon the user's credentials/token inthe account of the second cloud infrastructure. Consent for setting upthe resource principal is provided by the user when the user requests anew account using the multi-cloud console or requests the user's accountin the first cloud infrastructure to be linked to the user's account inthe second cloud infrastructure. Further, as shown in step 4, thecloud-link resource principal is transmitted to the downstream serviceto enable the user to utilize the downstream service(s) (e.g., one ormore services provided by the first cloud infrastructure) from thesecond cloud infrastructure.

Turning to FIG. 8B, there is depicted processing related to linking anexisting account or tenancy in the first cloud infrastructure to anaccount of the user in the second cloud infrastructure. As shown in FIG.8B, the user, via the sign-up UI provided by the multi-cloud console,requests the user's accounts in the first cloud infrastructure and thesecond cloud infrastructure to be linked. In response, in step 1, themulti-cloud console makes a call to the cloud-link adaptor to link theaccounts. Such a call may be made using one of the APIs exposed by thecloud-link adaptor to the sign-up UI. In certain implementations, theinformation passed to the cloud-link adaptor in step 1, includesinformation identifying the user's account in the second cloudinfrastructure and also the user's account in the first cloudinfrastructure, a token issued by the second cloud infrastructure, etc.

At step 2, the cloud-link adaptor makes a call to the authority/proxymodule included in the multi-cloud infrastructure to authenticate thetoken received in step 1. As part of this authentication, theauthority/proxy module determines whether the user making the requesthas sufficient authority on the second cloud infrastructure side to makethe linkage request. As part of the validation, roles and permissionsset up on the second cloud infrastructure side may be checked. Inresponse to the user being successfully validated, the cloud-linkadaptor retrieves from the data object previously created for the user,the resource-principal associated with a resource that is desired to beutilized by the user. Further, as shown in step 3, the cloud-linkresource principal is transmitted to the downstream service to enablethe user to utilize the downstream service(s) (e.g., one or moreservices provided by the first cloud infrastructure) from the secondcloud infrastructure.

FIG. 9 depicts an exemplary system diagram illustrating components of amulti-cloud control plane (MCCP) according to some embodiments. The MCCP900 includes a service platform (SPLAT) 910, a routing proxy 915, acloud-link adaptor 920, a database adaptor 925, a network adaptor 930,and an MCCP platform 935. Upon the user successfully completing thesign-up process as described above with reference to FIGS. 8A and 8B,the user may utilize the multi-cloud console 905 to issue commands toaccess, create, or update a resource in the tenancy of the user in thefirst cloud infrastructure. For sake of illustration, in what follows,there is described a scenario of the user utilizing the multi-cloudconsole to issue a request to create an Exa-database resource.

In some implementations, the user accesses the multi-cloud console 905and provides login information e.g., credentials of the user in thesecond cloud infrastructure. The multi-cloud console 905 provides aplurality of options e.g., create a resource, access a resource, updatea resource etc. Such options may be provided to the user in the form ofselectable icons (e.g., buttons) in the multi-cloud console 905. Uponthe user performing a selection (e.g., to create a resource), an APIcall is triggered to the service platform 910. It is appreciated thatthe request made to the service platform 910 is not a native call withrespect to the first cloud infrastructure. Rather, the call is a RESTtype call including an authorization header that comprises a tokenassociated with the user in the second cloud infrastructure.

The REST call including the token is further forwarded to the routingproxy module 915 that performs authentication and access controloperations. According to some embodiments, the routing proxy module 915performs an authentication operation by extracting the token included inthe REST call. The routing proxy module 915 validates the token bycomparing a signature (used to sign the request) with a publiclyavailable signature of the second cloud infrastructure to ensure thatthe request originates from a valid customer associated with the secondcloud infrastructure. Additionally, the routing proxy module 915 mayalso check roles i.e., privileges associated with the token e.g.,whether the role corresponds to an Exadata DB administrator or the like.Based on the role, the routing proxy module 915 may route the request toan appropriate adaptor included in the MCCP framework 900.

According to one embodiment, the routing proxy module 915 compares therole (associated with the token) to a preconfigured list of roles thatis published and assigned (as part of the API specification) for each ofthe adaptors. For example, if the role associated with the tokencorresponds to an ‘Exadata DB administrator’, then the request may becomprehended as one being of creating an Exa-database and thus therequest is forwarded to the database adaptor 925. Additionally, by someembodiments, the routing proxy module 915 may analyze informationincluded in the REST call such as a provider ID, resource typerequested, etc., and based on the analyzed information, the routingproxy module 915 may forward the request to the appropriate adaptor.

In some implementations, the request obtained by the routing proxymodule 915 may not include information identifying the tenancy of theuser in the first cloud infrastructure where the resource is to bedeployed. Thus, the routing proxy module 915 communicates with thecloud-link adaptor 920 to obtain mapping information of the user'saccount in the second cloud infrastructure to the tenancy of the user inthe first cloud infrastructure. If the mapping information exists, thenthe routing proxy module 915 obtains the information pertaining to thetenancy of the user in the first cloud infrastructure and passes theinformation to the database adaptor 925. In this manner, the databaseadaptor 925 is aware of the tenancy of the user in the first cloudinfrastructure where the resource is to be created/deployed. However, ifthe cloud-link adaptor 920 determines that no mapping informationexists, then the routing proxy module 915 may simply issue, as aresponse to the request to create the database resource, an‘unauthorized-access’ message that is transmitted back to the user.

It is noted that in some implementations, the cloud-link adaptor 920creates a data object (referred to herein as a cloud-link resourceobject) for storing metadata information identifying the two accountsbeing linked. For example, the data object stores metadata informationincluding a mapping of a first identifier associated with the tenancy(i.e., account) in the first cloud infrastructure and a secondidentifier associated with the account of the user with the second cloudservice provider. Additionally, the cloud-link adaptor 920 also createsa resource-principal (referred to herein as a cloud-link resourceprincipal) for a resource (e.g., database) that is desired to becreated/managed by the user of the second cloud infrastructure. Thecloud-link adaptor 920 may maintain the data object as well as theresource-principal within a root compartment of the tenancy of the userin the first cloud infrastructure. In some embodiments, the cloud-linkadaptor 920 may also locally persist the data object and/or the resourceprincipal in the MCCP platform 935.

In some embodiments, the database adaptor 925 may communicate with (orinstruct) the network adaptor 930 to create a network link between theuser's account in the second cloud infrastructure and the tenancy of theuser in the first cloud infrastructure. For instance, the networkadaptor 930 may obtain from the native services in the second cloudinfrastructure module 945, a token associated with the user and create:(1) a first peering relationship (in the first cloud environment)between a data plane of the MCCP and the tenancy of the user in thefirst cloud infrastructure, and (2) a second peering relationship (inthe second cloud environment) between the user's account and asubscription of the first cloud provider included in the second cloudinfrastructure.

The network adaptor 930 is also configured to establish networkconnectivity between the first cloud infrastructure and the second cloudinfrastructure i.e., the network adaptor 930 can configure aninterconnect (e.g., interconnect 719 of FIG. 7 ) that communicativelycouples the two cloud environments. It is appreciated that upon formingthe network link between the tenancy of the user in the first cloudinfrastructure and the account of the user in the second cloudinfrastructure, applications that are executed in the user'ssubscription/account are able to access resources e.g., Exa-databasedeployed in the tenancy of the first cloud infrastructure. Furthermore,the creation of the peering relationships provisions for metrics e.g.,database usage metrics to be accessible in the second cloudinfrastructure e.g., in a dashboard application that is executed in thesubscription of the user in the second cloud infrastructure.

In some implementations, the database adaptor 925 may obtain theresource principal that is locally persisted in the MCCP platform 935.The database adaptor 925 may transmit a request (including theresource-principal) to one or more downstream services included in thefirst cloud infrastructure 940 to create the resources in the tenancy ofthe user in the first cloud infrastructure. In other words, thedownstream services included in the first cloud infrastructure 940utilizes the identity i.e., resource principal obtained from the MCCPplatform 935 to create/deploy the required resources e.g., Exa-databasein the tenancy of the user in the first cloud infrastructure. Upon theuser issuing the request to create the Exa-database, the user mayintermittently poll the MCCP 900 to obtain a status of the request. Uponthe downstream services of the first cloud infrastructure 940 creatingthe resource in the tenancy of the user in the first cloudinfrastructure, and the network adaptor 930 establishing the peeringrelationships, the MCCP 900 may notify the user regarding a successfulcompletion of the request.

Multi Cloud Network Service—Network Adaptor

Referring to FIG. 7 , the architecture of the multi-cloud control plane700 enables a customer of an external cloud environment (that isprovided by an external cloud services provider) e.g., the second cloudenvironment 710, to deploy resources (e.g., database resources), executea service, etc., provided in a first cloud environment 720 by utilizingthe multi-cloud console 721 and the multi-cloud infrastructure 720B(included in the first cloud environment). In some implementations,network connectivity between the first cloud environment and the secondcloud environment is to be configured and maintained in order to exposeservice offerings (e.g., PaaS offerings) of the first cloud environmentto customers of the second cloud environment. As described below indetail, a network adaptor (e.g., the network-link component 722F of FIG.7 ) is responsible for handling such network related resources.

In certain embodiments, there is provided a multi-cloud network (MCN)service that is responsible for configuring and maintaining the networkconnectivity between the first cloud environment and other cloudenvironments e.g., the second cloud environment. MCN exposes servicessuch as PaaS offerings to customers of the other cloud environments is aseamless manner. It is appreciated that the MCN service fits into thearchitecture of the multi-cloud control plane 700 of FIG. 7 as theNetwork Adaptor component 722F. According to some embodiments, the MCNservice is responsible for:

-   -   1. Integrating with a multi-cloud platform and exposing a        customer-facing API object referred to as network-link, which        will serve as a cross-cloud virtual network interconnect        abstraction to the customer.    -   2. Configure and maintain direct interconnect links (e.g.,        ExpressRoute, FastConnect, etc.,) between external cloud        environments and the first cloud environment to be shared across        N customers.    -   3. Launch and monitor per-customer packet processor instances to        enable end-to-end packet flow between external cloud        environments and the first cloud environment.    -   4. Configure any domain name system (DNS) related resources in        external cloud environments and the first cloud environment to        allow seamless name resolutions.

Network-Link, as the name suggests, is an abstraction that interconnectstwo cloud environments. For example, the network-link may interconnect acustomer's virtual network in in the second cloud environment to acustomer's virtual cloud network (VCN) in the first cloud environment.It is appreciated that if a customer has to manually set up thenetwork-link, the customer is responsible for a multitude of tasks suchas configuring an interconnect (e.g., Express Route) for the secondcloud environment, configuring another interconnect (e.g., Fast Connect)for the first cloud environment, configuring dynamic routing gateways,configuring gateway attachments and route tables, etc. Such tasks are byno means trivial in nature and moreover cause a poor customerexperience. As described by embodiments of the present disclosure, thereis provided the multi-cloud network (MCN) service which automaticallyconfigures the network-link (and related networking resources) withminimal to no customer interaction(s). Thus, by utilizing the MCNservice, customers need not have to worry about the internals of thenetwork-link component offered by the multi-cloud infrastructure of thefirst cloud environment, but simply use the network-link as a black-boxthat allows traffic to and from virtual networks of the customer indifferent cloud environments. Additionally, it is noted that thenetwork-link which is established between the different cloudenvironments may be required to have a very low transmission latency.This is due to the fact that resources deployed in the first cloudenvironment may be resources such as Exa-database resources which handleonline transaction processing events. As such events demand minimallatency, the multi-cloud network (MCN) service of the present disclosureis relied upon to establish, between different cloud environments, ahighly performative and highly available end-to-end network link with alow transmission latency.

FIG. 10 depicts a high-level block diagram of a network-link componentaccording to certain embodiments. Specifically, FIG. 10 depicts anetwork-link component 1007 (also referred to herein as a multi-cloudnetwork infrastructure (MCNI)) that is established between a first cloudenvironment 1005 and a second cloud environment 1010. As shown in FIG.10 , the network-link component 1007 is established between a customer'svirtual network (VNET) e.g., VNET 1022 included in the second cloudenvironment 1010 to a customer's virtual cloud network (VCN) 1012 i.e.,a VNET in the first cloud environment 1005. Thus, a resource 1013 (e.g.,exa-database) hosted in the customer's VCN 1012 (in the first cloudenvironment 1005) may be accessed/utilized by a virtual machine 1023that is hosted in the customer's VNET 1022 in the second cloudenvironment 1010.

As shown in FIG. 10 , on the second cloud environment side, thenetwork-link component 1007 includes a VNET (labeled as a leaf VNET)1019 that peers with the customer's VNET 1022 included in the secondcloud environment 1010. Any traffic to and from the customer's VCN 1012is put onto this VNET peering. It is noted that the leaf VNET 1019appears as a generic “network-link VNET” to the customer. On the firstcloud environment side, the network-link component 1007 has a dynamicrouting gateway (DRG) attachment, named Multi-Cloud Attachment 1017. Insome implementations, a customer may attach one's VCN (e.g., customerVCN 1012) to a customer owned DRG 1015 using VCN Attachment, and theMCNI 1007 is linked into this DRG 1015 via the Multi-Cloud Attachment1017. It is noted that any traffic to and from the customer VNET 1022(included in the second cloud environment 1010) is put onto VCNattachment, and then to the Multi-Cloud Attachment 1017 within the DRG.

As will described below with reference to FIGS. 11 and 13 , someportions of the network-link component 1007 will be included in thefirst cloud environment 1005, whereas some other portions of thenetwork-link component 1007 will be included in the second cloudenvironment 1010. Furthermore, it is appreciated that one of the goalsof the network-link component 1007 is to construct a multi-tenanttunneling infrastructure to share the interconnect(s) between the firstcloud environment and the second cloud environment. In order formulti-tenant traffic to share a single inter-cloud interconnect, it isnoted that the network-link component 1007 provisions for tunnelling toencapsulate/de-capsulate customer traffic e.g., by using GENEVE tunnels.

Turning to FIG. 11 , there is depicted a detailed architecture 1100 of anetwork-link configuration according to certain embodiments. As shown inFIG. 11 , the network-link communicatively couples a region of a secondcloud environment 1105 to a region of a first cloud environment 1135.The region of the second cloud environment 1105 may include one or morecustomer VNETs. For example, the region of the second cloud environment1105 includes two customer VNETs i.e., customer 1 VNET 1101, andcustomer 2 VNET 1102. Accordingly, a portion of the second cloudenvironment 1105 hosting the customer VNETs is represented as customerdomain 1150A. Similarly, the region of the first cloud environment 1135may include one or more customer VCNs (i.e., customer virtual networks).For example, the region of the first cloud environment 1135 includes twocustomer VCNs i.e., customer 1 VCN 1131, and customer 2 VCN 1132.Accordingly, a portion of the first cloud environment 1135 hosting thecustomer VCNs is represented as customer domain 1150C.

According to some embodiments, a multi-cloud network infrastructure(MCNI) domain 1150B i.e., network-link, communicatively couples a pairof customer virtual networks. For instance, as shown in FIG. 11 ,customer 1 VNET 1101 (included in the region of the second cloudenvironment 1105) is communicatively coupled with customer 1 VCN 1131(included in the region of the first cloud environment 1135). In asimilar manner, customer 2 VNET 1102 (included in the region of thesecond cloud environment 1105) is communicatively coupled with customer2 VCN 1132 (included in the region of the first cloud environment 1135).It is noted that the MCNI domain 1150 corresponds to the network-linkdomain and is disposed between the dotted lines 1160 and 1170. Morespecifically, the MCNI domain includes a first portion that is disposedin the region of the second cloud environment 1105 and a second portionthat is disposed in the region of the first cloud environment 1135.

In some implementations, each pair of customer virtual networks (e.g.,customer 1 VNET 1101 in the region of the second cloud environment 1105,and customer 1 VCN 1131 in the region of the first cloud environment1135) is communicatively coupled using a plurality of virtual networks(referred to herein as link-enabling virtual networks), that aredeployed (in the first cloud environment and the second cloudenvironment) by the multi-cloud network (MCN) service. For example, afirst link-enabling virtual network 1103 (labeled as a leaf 1 VNET) anda second link-enabling virtual network 1107 (labeled as Spoke 1 VNET)are deployed in the region of the second cloud environment 1105 andassociated with customer 1 VNET 1101. Further, a third link-enablingvirtual network 1123 (labeled as a Spoke 1 VCN) is deployed in theregion of the first cloud environment 1135 and associated with customer1 VCN 1131. In a similar manner, customer 2 VNET 1102 is associated witha link-enabling virtual network 1104 (labeled as a leaf 2 VNET) andanother link-enabling virtual network 1106 (labeled as Spoke 2 VNET)that are deployed in the region of the second cloud environment 1105,whereas customer 2 VCN 1132 is associated with a different link-enablingvirtual network 1124 (labeled as spoke 2 VCN). Thus, in the architectureof FIG. 11 , each pair of customer virtual networks is associated withthree link-enabling virtual networks.

Further, the region of the second cloud environment 1105 includes a HubVNET 1110 that is shared between the different customer virtual networksincluded in the second cloud environment. In other words, Hub VNET 1110processes traffic for the plurality of customer tenancies included inthe region of the second cloud environment 1105. Similarly, the regionof the first cloud environment 1135 includes a Hub VNET 1122 that isshared between the different customer's virtual cloud networks includedin the first cloud environment i.e., Hub VNET 1122 processes traffic forthe plurality of customer VCNs included in the region of the first cloudenvironment 1135. As shown in FIG. 11 , the region of the second cloudenvironment 1105 is communicatively connected to the region of the firstcloud environment 1135 by a high-bandwidth network interconnect 1115. Inwhat follows, there is provided a detailed description of configuring anend-to-end network path between the customer 1 VNET 1101 (included inthe region of the second cloud environment 1105) and the customer 1 VCN1131 (included in the region of the first cloud environment 1135).

As shown in FIG. 11 , the first link-enabling virtual network 1103(i.e., Leaf 1 VNET) is peered to the customer 1 VNET 1101 in order toreceive traffic from virtual machines (e.g., operated by user 1101A)that are executed in the customer 1 VNET 1101. As the Hub VNET 1110 isshared across multiple customer VNETs in the region of the second cloudenvironment 1105, in some implementations of the present disclosure, anencapsulation and tunneling framework is utilized to differentiatebetween different customer traffic originating from the customer VNETsin the region of the second cloud environment 1105. The firstlink-enabling virtual network 1103 includes a pair of network adaptors1103A (referred to herein as remote virtual network adaptors (RVNA)).Each of the network adaptors 1103A included in the first link-enablingvirtual network 1103 is configured to encapsulate traffic received fromthe customer 1 VNET 1101 to generate encapsulated traffic.

In some implementations, the pair of network adaptors 1103A is used forpurposes of achieving high availability and is maintained in anactive-active state. In other words, each adaptor included in the pairof network adaptors 1103A is functional and encapsulates trafficreceived from the customer 1 VNET 1101. In some embodiments, the pair ofnetwork adaptors 1103A may utilize a service provided by the secondcloud environment 1105 for purposes of performing BGP peering. The pairof network adaptors 1103A may instruct such a service to spread traffic(originating from customer VNET) in a uniform manner, by usingmechanisms such as equal cost multi-path routing (ECMP). For example,considering that the second cloud environment 1105 corresponds to anAzure cloud (i.e., cloud operated by Microsoft), the pair of networkadaptors 1103A may utilize an Azure route server (ARS) for purposes ofperforming BGP peering.

However, utilization of such a service (e.g., ARS) of the second cloudenvironment poses some limitations. For example, services such as ARScan only learn and propagate routes in directly peered VNETs—this meansthat in order for the service to inject RVNA routes into customer'sVNET, the service (provided by the second cloud environment) needs toeither exist in the first link-enabling virtual network (i.e., Leaf VNET1103), or in a separate VNET that is directly peered with customer VNET1101. In order to avoid customer confusion by having two VNETs peer intotheir network, by one embodiment of the present disclosure, it ispreferred to have the service (e.g., ARS) be placed in the firstlink-enabling virtual network 1103.

According to some embodiments, a limitation of some types of secondcloud environments is that it forbids route-propagation across the VNETsif both the VNETs in the peering have either a virtual network gateway(VNG) or the service (e.g., ARS) deployed within it. Since hub VNET 1110has a VNG 1112 and the first link-enabling virtual network 1103 wouldhost the service (e.g., ARS), peering these two VNETs directly wouldmean that routes for hub VCN 1122 CIDR next-hopped to VNG would not getinstalled automatically, nor be configurable via user defined routes(UDR). As such, an additional layer of network-indirection is introducedbetween the first link-enabling virtual network 1103 and the Hub VNET1110. Specifically, as shown in FIG. 11 , a second link-enabling virtualnetwork 1107 is introduced as a next hop, to forward traffic from thefirst link-enabling virtual network 1103 to the Hub VNET 1110.

The second link-enabling virtual network 1107 includes a pair of virtualnetwork forwarders (VNF) 1107A. Each VNF included in the pair of VNFs1107A is configured to forward the encapsulated traffic received fromthe first link-enabling virtual network 1103 to the Hub virtual network1110 included in the region of the second cloud environment 1105. Insome implementations, the pair of virtual network forwarders (VNFs)1107A perform network address translation (NAT) with respect to theencapsulated traffic that is received from the first link-enablingvirtual network 1103. Specifically, the pair of virtual networkforwarders (VNFs) 1107A performs a NAT operation on each data packetthat is received from the first link-enabling virtual network 1103 suchthat the data packet is transmitted to a virtual network interface card(VNIC) e.g., VNIC 1122A included in the Hub VCN 1122 of the region ofthe first cloud environment 1135. It is appreciated that the pair ofvirtual network forwarders (VNF) 1107A forwards traffic to the VNG 1112included in the Hub VNET 1110, whereafter the traffic is communicatedover to the Hub VCN 1122 (included in the region of the first cloudenvironment 1135) via the high-bandwidth interconnect 1115.

According to some embodiments, encapsulated traffic received by the VNIC(e.g., VNIC 1122A) included in the Hub VCN 1122 is forwarded to a thirdlink-enabling virtual network 1123 (labeled as Spoke VCN) included inthe region of the first cloud environment 1135. The third link-enablingvirtual network 1123 includes a pair of virtual network adaptors 1123A(labeled as local virtual network adaptors (LVNAs)), each of which isconfigured to decapsulate, the encapsulated traffic received from theVNIC 1122A included in the Hub VCN 1122. Further, as shown in FIG. 11 ,the pair of virtual network adaptors 1123A included in the thirdlink-enabling virtual network 1123 of the first cloud environment 1135transmit the decapsulated traffic to the customer 1 VCN 1131 (e.g., to aresource 1131A that is deployed in the customer 1 VCN 1131) via adynamic routing gateway (DRG) attachment.

In this manner, an end-to-end network link is established between thecustomer 1 VNET 1101 in the region of the second cloud environment 1105to the customer 1 VCN 1131 in the region of the first cloud environment1135 via the first link-enabling virtual network 1103, the secondlink-enabling virtual network 1107, the Hub VNET 1110 (in the firstcloud environment), the Hub VCN 1122 (in the second cloud environment),and the third link-enabling virtual network 1123. It is appreciated thata network-link can be established between the customer 2 VNET 1102 (inthe region of the second cloud environment 1105) to the customer 2 VCN1132 (in the region of the first cloud environment 1135) in a mannersimilar to that as described above with respect to the network-linkestablished between customer 1 VNET and customer 1 VCN. Additionally, itis noted that although customer virtual networks in the first cloudenvironment and the second cloud environment may share an IP addressspace, each of the first link-enabling virtual network, the secondlink-enabling virtual network, the third link-enabling virtual network,and the HUB virtual networks included in the first cloud environment andthe second cloud environment are assigned a unique classlessinter-domain routing IP address space to avoid traffic collision.

FIGS. 12A and 12B depict exemplary latency values observed for thearchitecture of the network-link of FIG. 11 , according to certainembodiments. Specifically, the architecture of the network-linkdiscussed above with reference to FIG. 11 results in an observed latency(corresponding to, for example, communication path between customer 1VNET and customer 1 VCN, as shown by the dotted lines) to have latencyof 3 milliseconds. A breakdown of the latency observed between theindividual components on said path is depicted in FIG. 12A. It is notedthat in the case depicted in FIG. 12A, the RVNAs and VNFs are randomlyplaced in the second cloud environment. According to some embodiments,using a placement strategy, wherein the RVNAs and VNFs are placed inaccordance with some condition (as opposed to being randomly placed)results in an improvement of the observed latency. For instance, placingthe RVNAs and VNFs (i.e., that are associated with a customer's virtualnetwork) in a same zone (e.g., availability zone of the second cloudenvironment) results in an improvement of the observed latency. Forinstance, as shown in FIG. 12B, which provides the latency breakdownbetween the individual components, it is observed that the end-to-endlatency is reduced from 3 milliseconds down to 1.6 milliseconds byplacing the RVNAs and the VNFs in the same availability domain of thesecond cloud environment.

FIG. 12C depicts an exemplary flowchart illustrating a process ofestablishing a network-link according to certain embodiments. Theprocessing depicted in FIG. 12C may be implemented in software (e.g.,code, instructions, program) executed by one or more processing units(e.g., processors, cores) of the respective systems, hardware, orcombinations thereof. The software may be stored on a non-transitorystorage medium (e.g., on a memory device). The method presented in FIG.12C and described below is intended to be illustrative and non-limiting.Although FIG. 12C depicts the various processing steps occurring in aparticular sequence or order, this is not intended to be limiting. Incertain alternative embodiments, the steps may be performed in somedifferent order or some steps may also be performed in parallel.

The process commences in step 1250, where a multi-cloud infrastructurethat is included in a first cloud environment (e.g., multi-cloudinfrastructure 720B of FIG. 7 ), receives a request to create anetwork-link between a first virtual network (e.g., customer 1 VCN 1131of FIG. 11 ) in the first cloud environment and a second virtual network(e.g., customer 1 VNET 1101 of FIG. 11 ) in a second cloud environment.It is noted that the first virtual network in the first cloudenvironment is created previously in order to enable a user associatedwith a customer tenancy in the second cloud environment 1105 to accessone or more services provided in the first cloud environment 1135.Thereafter, the process proceeds to step 1260 for creating thenetwork-link between the first virtual network and the second virtualnetwork.

The process of creating the network-link in step 1260 includesencapsulating, by a first link-enabling virtual network in the secondcloud environment, traffic that is received from the second virtualnetwork to generate encapsulated traffic. For example, referring to FIG.11 , the first link-enabling virtual network 1103, which includes RVNAs,encapsulates the traffic received from the customer 1 VNET 1101 (step1263).

Further, in step 1265, a second link-enabling virtual network (e.g., thelink-enabling virtual network 1107 in FIG. 11 ) in the second cloudenvironment forwards (e.g., via VNFs) the encapsulated traffic receivedfrom the first link-enabling virtual network to a hub virtual network(e.g., Hub VNET 1110) included in the second cloud environment. Theprocess then moves to step 1267 where a third link-enabling virtualnetwork (e.g., the link-enabling virtual network 1123 of FIG. 11 ) inthe first cloud environment, decapsulates (e.g., via the LVNAs) theencapsulated traffic received from the hub virtual network e.g., Hub VCN1122. Further, in step 1269, the third link-enabling virtual network inthe first cloud environment transmits the decapsulated traffic to thefirst virtual network (e.g., customer 1 VCN 1131 of FIG. 11 ) in thefirst cloud environment via a DRG attachment. In this manner, themulti-cloud infrastructure of the present disclosure configures ahigh-performant, highly available, and low latency network-link betweendifferent customer virtual networks.

Turning to FIG. 13 , there is depicted a detailed architecture 1300 of anetwork-link configuration according to certain embodiments. As shown inFIG. 13 , the network-link communicatively couples a region of a secondcloud environment 1305 to a region of a first cloud environment 1335.The region of the second cloud environment 1305 may include one or morecustomer VNETs. For example, the region of the second cloud environment1305 includes two customer VNETs i.e., customer 1 VNET 1301, andcustomer 2 VNET 1302. Accordingly, a portion of the second cloudenvironment 1305 hosting the customer VNETs is represented as customerdomain 1350A. Similarly, the region of the first cloud environment 1335may include one or more customer VCNs (i.e., customer virtual networks).For example, the region of the first cloud environment 1335 includes twocustomer VCNs i.e., customer 1 VCN 1331, and customer 2 VCN 1332.Accordingly, a portion of the first cloud environment 1335 hosting thecustomer VCNs is represented as customer domain 1350C.

According to some embodiments, a multi-cloud network infrastructure(MCNI) domain 1350B i.e., network-link, communicatively couples a pairof customer virtual networks. For instance, as shown in FIG. 13 ,customer 1 VNET 1301 (included in the region of the second cloudenvironment 1305) is communicatively coupled with customer 1 VCN 1331(included in the region of the first cloud environment 1335). In asimilar manner, customer 2 VNET 1302 (included in the region of thesecond cloud environment 1305) is communicatively coupled with customer2 VCN 1332 (included in the region of the first cloud environment 1335).It is noted that the MCNI domain 1350 corresponds to the network-linkdomain and is disposed between the dotted lines 1360 and 1370. Morespecifically, the MCNI domain includes a first portion that is disposedin the region of the second cloud environment 1305 and a second portionthat is disposed in the region of the first cloud environment 1335.

In some implementations, each pair of customer virtual networks (e.g.,customer 1 VNET 1301 in the region of the second cloud environment 1305,and customer 1 VCN 1331 in the region of the first cloud environment1335) is communicatively coupled using a plurality of virtual networks(referred to herein as link-enabling virtual networks), that aredeployed (in the first cloud environment and the second cloudenvironment) by the multi-cloud network (MCN) service. For example, afirst link-enabling virtual network 1303 (labeled as a leaf 1 VNET) isdeployed in the region of the second cloud environment 1305. A secondlink-enabling virtual network 1323 (labeled as Spoke 1 VCN) is deployedin the region of the first cloud environment 1335. In a similar manner,customer 2 VNET 1302 is associated with a link-enabling virtual network1304 (labeled as a leaf 2 VNET) and another link-enabling virtualnetwork 1324 (labeled as Spoke 2 VCN) that are deployed in the region ofthe second cloud environment 1305 and the region of the first cloudenvironment 1335, respectively. Thus, in the architecture of FIG. 13 ,each pair of customer virtual networks is associated with twolink-enabling virtual networks.

Further, the region of the second cloud environment 1305 includes a HubVNET 1310 that is shared between the different customer virtual networksincluded in the second cloud environment. In other words, Hub VNET 1310processes traffic for the plurality of customer tenancies included inthe region of the second cloud environment 1305. Similarly, the regionof the first cloud environment 1335 includes a Hub VCN 1322 that isshared between the different customer's virtual cloud networks includedin the first cloud environment i.e., Hub VCN 1322 processes traffic forthe plurality of customer VCNs included in the region of the first cloudenvironment 1335. As shown in FIG. 13 , the region of the second cloudenvironment 1305 is communicatively connected to the region of the firstcloud environment 1335 by a high-bandwidth network interconnect 1315. Inwhat follows, there is provided a detailed description of configuring anend-to-end network path between the customer 1 VNET 1301 (included inthe region of the second cloud environment 1305) and the customer 1 VCN1331 (included in the region of the first cloud environment 1335).

As shown in FIG. 13 , the first link-enabling virtual network 1303(i.e., Leaf 1 VNET) is peered to the customer 1 VNET 1301 in order toreceive traffic from virtual machines (e.g., operated by user 1301A)that are operated in the customer 1 VNET 1301. As the Hub VNET 1310 isshared across multiple customer VNETs in the region of the second cloudenvironment 1305, in some implementations of the present disclosure, anencapsulation and tunneling framework is utilized to differentiatebetween different customer traffic originating from the customer VNETsin the region of the second cloud environment 1305. The firstlink-enabling virtual network 1303 includes a pair of network adaptors1303A (referred to herein as remote virtual network adaptors (RVNA)).Each of the network adaptors 1303A included in the first link-enablingvirtual network 1303 is configured to encapsulate traffic received fromthe customer 1 VNET 1301 to generate encapsulated traffic.

In some implementations, the pair of network adaptors 1303A is used forpurposes of achieving high availability and is maintained in anactive-active state. In other words, each adaptor included in the pairof network adaptors 1303A is functional and encapsulates trafficreceived from the customer 1 VNET 1301. In some embodiments, the pair ofnetwork adaptors 1303A may utilize a service provided by the secondcloud environment 1305 for purposes of performing BGP peering. The pairof network adaptors 1303A may instruct such a service to spread traffic(originating from customer VNET) in a uniform manner, by usingmechanisms such as equal cost multi-path routing (ECMP).

As shown in FIG. 13 , the Hub VNET 1310 includes pairs of virtualnetwork forwarders (VNF) 1306 and 1307. A pair of VNFs are associatedfor each customer VNET included in the region of the second cloudenvironment 1305. For example, the pair of VNFs 1307 is associated withcustomer 1 VNET 1301 and the pair of VNFs 1306 is associated withcustomer 2 VNETs 1301. Each VNF included in the pair of VNFs 1307 isconfigured to forward the encapsulated traffic received from the firstlink-enabling virtual network 1303 (i.e., from the corresponding RVNAs)to the Hub virtual network 1322 included in the region of the firstcloud environment 1335.

In some implementations, the pair of virtual network forwarders (VNFs)1307 perform network address translation (NAT) with respect to theencapsulated traffic that is received from the first link-enablingvirtual network 1303. Specifically, the pair of virtual networkforwarders (VNFs) 1307 performs a NAT operation on each data packet thatis received from the first link-enabling virtual network 1303, such thatthe data packet is transmitted to a virtual network interface card(VNIC) e.g., VNIC 1322A included in the Hub VCN 1322 of the region ofthe first cloud environment 1335. It is appreciated that the pair ofvirtual network forwarders (VNF) 1307 forwards traffic to a virtualnetwork gateway (VNG) 1312 included in the Hub VNET 1310, whereafter thetraffic is communicated over to the Hub VCN 1322 (included in the regionof the first cloud environment 1335) via the high-bandwidth interconnect1315.

According to some embodiments, encapsulated traffic received by the VNIC(e.g., VNIC 1322A) included in the Hub VCN 1322 is forwarded to a secondlink-enabling virtual network 1323 (labeled as Spoke VCN) included inthe region of the first cloud environment 1335. The second link-enablingvirtual network 1323 includes a pair of virtual network adaptors 1323A(labeled as local virtual network adaptors (LVNAs)), each of which isconfigured to decapsulate, the encapsulated traffic received from theVNIC 1322A included in the Hub VCN 1322. Further, as shown in FIG. 13 ,the pair of virtual network adaptors 1323A included in the secondlink-enabling virtual network 1323 of the first cloud environment 1335transmits the decapsulated traffic to the customer 1 VCN 1331 (e.g., toa resource 1331A that is deployed in the customer 1 VCN 1331) via adynamic routing gateway (DRG) attachment.

In this manner, an end-to-end network link is established between thecustomer 1 VNET 1301 in the region of the second cloud environment 1305,to the customer 1 VCN 1331 in the region of the first cloud environment1335 via the first link-enabling virtual network 1303, the secondlink-enabling virtual network 1323, the Hub VNET 1310 (in the firstcloud environment), and the Hub VCN 1322 (in the second cloudenvironment). It is appreciated that a network-link can be establishedbetween the customer 2 VNET 1302 (in the region of the second cloudenvironment 1305) to the customer 2 VCN 1332 (in the region of the firstcloud environment 1335) in a manner similar to that as described abovewith respect to the network-link established between customer 1 VNET andcustomer 1 VCN. Additionally, it is noted that although customer virtualnetworks in the first cloud environment and the second cloud environmentmay share an IP address space (e.g., have overlapping IP address space),each of the first link-enabling virtual network, the secondlink-enabling virtual network, and the HUB virtual networks included inthe first cloud environment and the second cloud environment areassigned a unique classless inter-domain routing IP address space toavoid traffic collision.

FIG. 14A depicts an exemplary observed latency breakdown for theinterconnect sharing structure of FIG. 13 , according to someembodiments. It is observed that in this configuration, the end-to-endlatency (for example path 1 from customer 1 VNET to customer 1 VCN) is950 micro-seconds. Accordingly, the present disclosure provides for astrategic placement of the packet processors e.g., VNFs being placed inthe Hub VNET that accomplishes a low latency which is advantageous forsupporting high-throughput and latency sensitive applications such asExa-database applications. It is noted that in the above-describedembodiments, the latency measurements correspond to a specific setup ofthe customer VNET and customer VCNs i.e., in the availability zones andregions.

FIG. 14B depicts another exemplary flowchart illustrating a process ofestablishing a network-link according to certain embodiments. Theprocessing depicted in FIG. 14B may be implemented in software (e.g.,code, instructions, program) executed by one or more processing units(e.g., processors, cores) of the respective systems, hardware, orcombinations thereof. The software may be stored on a non-transitorystorage medium (e.g., on a memory device). The method presented in FIG.14B and described below is intended to be illustrative and non-limiting.Although FIG. 14B depicts the various processing steps occurring in aparticular sequence or order, this is not intended to be limiting. Incertain alternative embodiments, the steps may be performed in somedifferent order or some steps may also be performed in parallel.

The process commences in step 1450, where a multi-cloud infrastructurethat is included in a first cloud environment (e.g., multi-cloudinfrastructure 720B of FIG. 7 ), receives a request to create anetwork-link between a first virtual network (e.g., customer 1 VCN 1331of FIG. 13 ) in the first cloud environment and a second virtual network(e.g., customer 1 VNET 1301 of FIG. 13 ) in a second cloud environment.It is noted that the first virtual network in the first cloudenvironment is created previously in order to enable a user associatedwith a customer tenancy in the second cloud environment 1305 to accessone or more services provided in the first cloud environment 1335.Thereafter, the process proceeds to step 1455 for creating thenetwork-link between the first virtual network and the second virtualnetwork using a plurality of link-enabling virtual networks.

The process then moves to step 1460, where a first link-enabling virtualnetwork from the plurality of link-enabling virtual networks is placedin the second cloud environment. For example, referring to FIG. 13 , thefirst link-enabling virtual network 1303 is deployed in the region ofthe second cloud environment to peer with a customer's VNET. The processin step 1465 places/deploys a second link-enabling virtual network fromthe plurality of link-enabling virtual networks is placed in the firstcloud environment. For example, referring to FIG. 13 , the secondlink-enabling virtual network 1323 is deployed in the region of thefirst cloud environment to peer with a customer's VCN via a DRGattachment. In this manner, the multi-cloud infrastructure of thepresent disclosure configures a high-performant, highly available, andlow latency network-link between different customer virtual networks.

FIG. 15 depicts an architecture of a service infrastructure 1500including a multi-cloud network service control plane (MCNS-CP),according to certain embodiments. The MCNS-CP is responsible forconfiguring network-links as those described above with reference toFIGS. 11 and 13 . As shown in FIG. 15 , the service architecture 1500includes a region of a second cloud environment 1501 and a region of afirst cloud environment 1551 that may be communicatively coupled to eachother via a high-bandwidth interconnect (e.g., Express Route or FastConnect). The region of the second cloud environment 1501 includes acustomer VNET 1503, a Spoke VNET 1505, a Leaf VNET 1507, a Hub VNET1509, and a multi-cloud service VNET 1510. The customer VNET 1503corresponds to a customer domain, whereas the Spoke VNET 1505 and theLeaf VNET 1507 correspond to a service domain that is instantiated percustomer. It is appreciated that the Hub VNET 1509 and the multi-cloudservice VNET 1510 correspond to portions of the service plane that aremulti-tenanted.

The Leaf VNET 1507 peers with the customer VNET 1503 and includes one ormore virtual network adaptors (e.g., RVNAs 1507A) that are configured toencapsulate/decapsulate traffic received from/to the customer VNET 1503.The Spoke VNET 1505 includes one or more virtual network forwarders(e.g., VNFs 1505A) that are configured to forward traffic received fromthe Leaf VNET 1507 to the Hub VNET 1509. Further, each of the Leaf VNET1507 and the Spoke VNET 1505 include private endpoints via which networkconfiguration information may be provided to the RVNAs and VNFs,respectively. For example, Leaf VNET 1507 includes a private endpoint1507B and the Spoke VNET 1505 includes a private endpoint 1505B viawhich, network configuration information (i.e., mapping information) canbe obtained. Details regarding distribution of the network configurationinformation are described below.

The Hub VNET 1509 includes a virtual network gateway (VNG) which iscommunicatively coupled to the high-bandwidth interconnect in order tocouple the second cloud environment to the first cloud environment. Insome implementations, the Hub VNET 1509 may include a Bastion 1509A,which is a fully platform-managed PaaS service that is provisioned in avirtual network. Specifically, the Bastion 1509 is a service thatenables one to connect to a virtual machine, for instance by using abrowser, via a native SSH, etc. The multi-cloud service VNET 1510includes an internal load balancer (ILB) 1510B and an outpost 1510A. Thecombination of the outpost 1510A and the ILB 1510B are used todistribute network configuration information (received from the firstcloud environment) to the private endpoints 1505B and 1507B. In thismanner, the VNF 1505A as well as the RVNA 1507A can receive networkconfiguration information from their respective private endpoints i.e.,private endpoint 1505B and private endpoint 1507B.

The region of the first cloud environment 1551 includes a customer VCN1557 that hosts a resource 1558 (e.g., exa-database), a Spoke VCN 1555,a Hub VCN 1553, and a multi-cloud service VCN 1560. The customer VCN1557 corresponds to a customer domain, whereas the Spoke VCN 1555corresponds to a service domain that is instantiated per customer. It isappreciated that the Hub VCN 1553 and the multi-cloud service VCN 1560correspond to portions of the service plane that are multi-tenanted.

The Spoke VCN 1555 peers with the customer VCN 1557 (e.g., via a DRGattachment) and includes one or more virtual network adapters (e.g.,LVNAs 1555A) that are configured to encapsulate/decapsulate trafficreceived from/to the customer VCN 1557. The Spoke VCN 1555 includes aVNIC attachment via which it communicates with the multi-cloud serviceVCN 1560. For example, the LVNAs 1555A included in the Spoke VCN 1555connect to a VNIC included in the multi-cloud service VCN 1560 on inorder to receive the network configuration information. The Spoke VCN1555 is further communicatively coupled to the Hub VCN 1553 via anotherVNIC attachment 1553B included in the Hub VCN 1553. The Hub VCN 1553includes a DRG via which the Hub VCN 1553 is coupled to thehigh-bandwidth interconnect that couples the first cloud environment tothe second cloud environment.

According to some embodiments, the multi-cloud service VCN 1560corresponds to a stack of the control plane that is built in the firstcloud environment 1551. Specifically, the multi-cloud service iscomposed of several networking resources such as VCNs, route tables,DRGs, attachments, VNETs, instances, VNICs, peerings, etc. Themulti-cloud service VCN 1560 includes a load balancer 1560A, one or moreAPI servers 1560B, a key-value store 1560 (labeled as a K-V store), adistribution service 1560D, workflow-as-a-service (WFaaS) workers 1560F,and a gateway 1560G. In some implementations, the one or more APIservers 1560B receive a request to setup the network-link between thefirst cloud environment and the second cloud environment. In response,the one or more API servers 1560B may initiate a worker (included in theWFaaS workers 1560F). In some implementations, the WFaaS workers 1560initiate communication with control planes of the first cloudenvironment and second cloud environment to deploy the requirednetworking resources to provision the network-link e.g., launch thelink-enabling virtual networks in the first cloud environment and thesecond cloud environment, and peer the network-link connections. Onesuch exemplary process performed by the WFaaS workers 1560F is describedlater with reference to FIG. 16A. The one or more API servers 1560B areconfigured to manage CIDR address allocation to the different componentsof the multi-cloud service.

The distribution service 1560D is a mapping service that receivesrequests (e.g., mapping requests) from RVNAs, VNFs, and LVNAs. Thedistribution service 1560D responds to such mapping requests byproviding the network configuration information required by the RVNAs,VNFs, and LVNAs to perform the encapsulation/decapsulation of networkpackets (i.e., traffic). For instance, in one implementation, the RVNAs,VNFs, and LVNAs may periodically poll the distribution service 1560D toobtain their respective network configuration information. Thedistribution service 1560D provides the network configurationinformation to the LVNA 1555A (located in the Spoke VCN 1555) via theVNIC attachment.

Further, the multi-cloud service VCN 1560 may setup a communicationchannel e.g., a tunnel (e.g., IPsec tunnel) with the multi-cloud serviceVNET 1510 in order to transmit the network configuration information tothe outpost 1510A (included in the multi-cloud service VNET 1510), sothat the network configuration information may be eventually obtained bythe VNF 1505A and RVNA 1507A (via their respective private endpoints)that are each located in the second cloud environment. Specifically,polling requests of the VNFs and RVNAs are received (via theirrespective endpoints 1505B and 1507B) by outpost 1510A. The outpost1510A in turn redirects such requests to the distribution service 1560D.In response to receiving the polling requests, the distribution service1560D provides the corresponding network configuration information tothe VNFs and RVNAs. In some implementations, the distribution service1560D obtains the network configuration information from the K-V store1560 and further distributes the obtained information to the differentpacket processors (i.e., VNFs, RVNAs, and LVNAs). It is appreciated thatthe distribution service 1560D may receive information indicative of ahealth status corresponding to each of the RVNAs, LVNAs, and VNFs in thepolling requests issued by the respective packet processors. Further,the multi-cloud service VCN 1560 includes the gateway 1560G, which isused to provision/enable calls/requests made by the multi-cloud serviceVCN 1560 to external parties e.g., calls made to the second cloudenvironment, call made to a public IP address, etc.

Turning to FIG. 16A, there is depicted a swim diagram illustratinginteractions of the multi-cloud service control plane with differentcloud environments, according to certain embodiments. The swim diagramof FIG. 16A depicts the interactions between the following entities: aclient 1601, a multi-cloud platform control plane 1602, a second cloudenvironment IaaS API 1603, and an IaaS API corresponding to the firstcloud environment 1604.

As shown in FIG. 16A, in step S1, a request issued by the client 1601 tocreate a network-link is received by the multi-cloud platform controlplane 1602. In some implementations, the multi-cloud platform controlplane 1602 accepts the request and provides an acknowledgement (step S2)back to the client 1601. Thereafter, the client 1601 may poll themulti-cloud platform control plane 1602 to obtain a status of therequest.

In step S3, upon accepting the request to create the network-link, themulti-cloud platform control plane 1602 initiates a workflow e.g., usingthe WFaaS workers (1560F of FIG. 15 ). In step S4, the multi-cloudplatform control plane 1602 transmits a first request to an IaaS APIcorresponding to the first cloud environment 1604. It is noted that sucha request may be transmitted to a first endpoint of the first cloudenvironment (e.g., the first endpoint may correspond to a resourcemanager of the first cloud environment). The first request correspondsto a request that is issued by the multi-cloud platform control plane1602 and requests the provisioning of a first set of resources in thefirst cloud environment. The first set of resources may correspond tocreation of LVNAs, Hub VCNs, Spoke VCNs, VNICs etc. It is appreciatedthat in some implementations, the first request may include a template,which requests the first endpoint, a collective instantiation of all therequired resources in the first cloud environment.

In step S5, the multi-cloud platform control plane 1602 transmits asecond request to an IaaS API corresponding to the second cloudenvironment 1603. It is noted that such a request may be transmitted toa second endpoint of the second cloud environment (e.g., the secondendpoint may correspond to a resource manager of the second cloudenvironment). The second request corresponds to a request that is issuedby the multi-cloud platform control plane 1602 and requests theprovisioning of a second set of resources in the second cloudenvironment. The second set of resources may correspond to creation ofRVNAs, VNFs, Hub VNET, Spoke VNET, service endpoints, network peerings,etc. It is appreciated that in some implementations, the second requestmay include a template, which requests the second endpoint, a collectiveinstantiation of all the required resources in the second cloudenvironment.

In steps 6 and 7, the multi-cloud platform control plane 1602 mayreceive acknowledgements from the first endpoint and the secondendpoint, respectively. Thereafter, upon receiving a polling requestfrom the client 1601 pertaining to a status of the requestednetwork-link, the multi-cloud platform control plane 1602 in step 9 maytransmit a message to the client indicating a successful creation of thenetwork-link (i.e., a message that indicates that the network-link isavailable).

FIG. 16B depicts an exemplary flowchart illustrating a process performedby the multi-cloud service control plane, according to certainembodiments. The processing depicted in FIG. 16B may be implemented insoftware (e.g., code, instructions, program) executed by one or moreprocessing units (e.g., processors, cores) of the respective systems,hardware, or combinations thereof. The software may be stored on anon-transitory storage medium (e.g., on a memory device). The methodpresented in FIG. 16B and described below is intended to be illustrativeand non-limiting. Although FIG. 16B depicts the various processing stepsoccurring in a particular sequence or order, this is not intended to belimiting. In certain alternative embodiments, the steps may be performedin some different order or some steps may also be performed in parallel.

The process commences in step 1650, where a control plane of amulti-cloud infrastructure that is included in a first cloudenvironment, receives a request to create a network-link between a firstvirtual network in the first cloud environment and a second virtualnetwork in a second cloud environment. It is noted that the firstvirtual network in the first cloud environment is previously created toenable a user associated with a customer tenancy in the second cloudenvironment to access one or more services provided in the first cloudenvironment. Upon receiving the request to create the network-link, thecontrol plane executes a workflow to commence the creation of thenetwork-link (step 1660).

In some implementations, the workflow may include several sub-steps thatare performed to create the network-link. For example, the workflow mayinclude step 1663, where a first request is transmitted to a firstendpoint of the first cloud environment (e.g., the first endpoint maycorrespond to a resource manager of the first cloud environment). Thefirst request corresponds to a request that is issued by the multi-cloudplatform control plane 1602 and requests the provisioning of a first setof resources in the first cloud environment. The first set of resourcesmay correspond to creation of LVNAs, Hub VCNs, Spoke VCNs, VNICs etc.

Thereafter, the process moves to step 1665, where a second request istransmitted to a second endpoint of the second cloud environment (e.g.,the second endpoint may correspond to a resource manager of the secondcloud environment). The second request corresponds to a request that isissued by the multi-cloud platform control plane 1602 and requests theprovisioning of a second set of resources in the second cloudenvironment. The second set of resources may correspond to creation ofRVNAs, VNFs, Hub VNET, Spoke VNET, service endpoints, network peerings,etc.

Further, in step 1670, responsive to the first set of resources and thesecond set of resources being provisioned, the control plane maydistribute, network configuration information to one or more resourcesin the first set of resources and the second set of resources. Thenetwork configuration information may include for example, informationcorresponding to an IP address of a resource. As such, the packetprocessors are provided information (via the distribution service of thecontrol plane) as to an address of next-hop destination to which thetraffic is to be forwarded. In other words, the network configurationinformation enables traffic to be communicated between the first virtualnetwork in the first cloud environment and the second virtual network inthe second cloud environment.

The architectures of the network-link created between a first cloudenvironment and a second cloud environment as described above withrespect to FIGS. 11 and 13 pertain to the location and placements ofpacket processors in the link-enabling virtual networks that are createdto provision the network-link. It is appreciated that the network-linkcreated by embodiments of the present disclosure support high-throughputand latency sensitive applications such as Exa-database applications.According to some embodiments, transmission latency (e.g., round-triplatency) of communication between the first cloud environment and thesecond cloud environment may also be affected by a selection of a domainin the first cloud environment and the second cloud environment, wherecompute instances are provisioned. In other words, it is desired toselect an optimal pair of domains (i.e., one domain in each of the firstcloud environment and the second cloud environment) to host the computeinstances in order to achieve low latency.

It is noted that a cloud infrastructure is typically hosted in regionsand domains (also referred to as availability domains). A region isdefined as a localized geographic area, and an availability domain maycorrespond to one or more data centers located within a region i.e., aregion is composed of one or more availability domains. Furthermore,cloud infrastructure resources may either be region-specific, such as avirtual cloud network, or availability domain-specific, such as acompute instance. Availability domains are isolated from each other,fault tolerant, and very unlikely to fail simultaneously. Becauseavailability domains do not share infrastructure such as power orcooling, or the internal availability domain network, a failure at oneavailability domain within a region is unlikely to impact theavailability of the others within the same region. Described below withreference to FIG. 17A is a framework for selecting availability domainsin the first cloud environment and the second cloud environment forplacement of compute instances such that a low latency is achieved intransmission of information from the first cloud environment to thesecond cloud environment and vice versa.

FIG. 17A depicts an exemplary placement strategy of compute instances inavailability domains of different cloud environments, according tocertain embodiments. For sake of simplicity and illustration, FIG. 17Adepicts a first cloud environment 1701 including three availabilitydomains (ADs) i.e., AD-1 1703A, AD-2 1703B, and AD-3 1703C. Similarly, asecond cloud environment 1721 is depicted as including threeavailability domains i.e., AD-1′ 1723A, AD-2′ 1723B, and AD-3′ 1723C.Customers in second cloud environment may desire to avail services(e.g., database services) provided by the first cloud environment.Certain types of services (e.g., Exa-database services) provided by thefirst cloud environment may be latency-sensitive as well as highthroughput. Thus, as shown in FIG. 17A, and according to someembodiments, one may require the deployment of one or more computeinstances 1720 in a particular availability domain in each cloudenvironment, for provisioning the service. It is appreciated that ADsare allocated to customers in a random manner. Specifically, AD 1, AD 2,and AD 3 that are allocated to customer 1 in a particular cloudenvironment may not correspond (with regard to the order) to the first,second, and third availability domains that are allocated for anothercustomer e.g., customer 2.

In the above-described framework, in order for a customer in the secondcloud environment to avail services provided by the first cloudenvironment, a selection of one AD in each cloud environment is to bedetermined such that one or more compute instances may be deployed inthe selected ADs to enable the desired service. It is noted that theselection of the pair of ADs (i.e., one AD in the first cloudenvironment and another AD in the second cloud environment) is to beperformed in a manner such that a latency incurred in providing theservice via the selected ADs is the least. Such a selection strategy ofthe ADs enables providing latency sensitive services.

According to some embodiments, the selection of an AD in each cloudenvironment is empirically derived in order to obtain the lowestlatency. In one implementation, the steps involved in selection of an ADin each cloud environment may be described as follows:

Step 1:—Assign a single compute instance (referred to herein as a testcompute instance) in each availability domain in each cloud environment.

Step 2:—Obtain transmission latency for each pair (k, j) of ADs, wherek=1, 2, 3 and j=1′, 2′, 3′. Note that latency corresponds to an amountof time incurred in transmission of data from a compute instancedeployed in one AD to another compute instance deployed in the other AD.

Step 3:—Select the pair of ADs having the lowest latency.

Step 4:—Shut down instances in ADs (in each cloud environment) that arenot selected and deploy a desired number of compute instances in each ADof the selected pair of ADs. In some applications, two compute instances(i.e., a primary compute instance and a secondary compute instance) maybe deployed in the selected AD of each cloud environment. For instance,as shown in FIG. 17A, AD-1 1703A in the first cloud environment andAD-2′ 1723B in the second cloud environment are determined as the pairof ADs that incur the lowest transmission latency. As such forprovisioning the service, two compute instances are deployed in each ofAD-1 1703A and AD-2′ 1723B.

According to some embodiments, it is noted that the two computeinstances may be deployed in different fault domains within the AD forpurposes of high availability. By some other embodiments, one may chooseto deploy one compute instance in the AD pair having the lowest latency,and another instance in another AD pair having the second lowestlatency. It is appreciated that other possible selections of ADs basedon the selection strategy discussed above are well within the scope ofthe present disclosure.

FIG. 17B depicts an exemplary flowchart illustrating a process performedby the multi-cloud service control plane in determining availabilitydomains of different cloud environments in which compute instances areto be deployed, according to certain embodiments. The processingdepicted in FIG. 17B may be implemented in software (e.g., code,instructions, program) executed by one or more processing units (e.g.,processors, cores) of the respective systems, hardware, or combinationsthereof. The software may be stored on a non-transitory storage medium(e.g., on a memory device). The method presented in FIG. 17B anddescribed below is intended to be illustrative and non-limiting.Although FIG. 17B depicts the various processing steps occurring in aparticular sequence or order, this is not intended to be limiting. Incertain alternative embodiments, the steps may be performed in somedifferent order or some steps may also be performed in parallel.

The process commences in step 1755, where a multi-cloud infrastructureincluded in a first cloud environment receives a request to deploy: (i)a first plurality of compute instances in a first availability domain ofa first plurality of availability domains in the first cloudenvironment, and (ii) a second plurality of compute instances in asecond availability domain of a second plurality of availability domainsin a second cloud environment. The first plurality of compute instancesin the first availability domain of the first cloud environment and thesecond plurality of compute instances in the second cloud environmentenable a user in the second cloud environment to access one or moreservices provided in the first cloud environment.

The process then moves to step 1760 to determine the first availabilitydomain of the first plurality of availability domains in the first cloudenvironment and the second availability domain of a second plurality ofavailability domains in a second cloud environment. In order todetermine the first and second availability domains, the process movesto step 1765, where the process iteratively performs a set of operationsfor each availability domain of the first plurality of availabilitydomains in the first cloud environment and each availability domain ofthe second plurality of availability domains in the second cloudenvironment. The iterative operations include steps 1765A-1765D.

In step 1765A, a first test compute instance is placed in theavailability domain of the first plurality of availability domains inthe first cloud environment. In step 1765B, a second test computeinstance is placed in the availability domain of the second plurality ofavailability domains in the second cloud environment. The iterativeprocess then moves to step 1765C, where a test packet is transmittedfrom the first test compute instance to the second test computeinstance. In step 1765D, a transmission latency corresponding to a pairof availability domains hosting the first test compute instance and thesecond test compute instance is computed. Upon iteratively processingthe steps 1765A-1765D, the process moves to step 1770, where the firstavailability domain in the first cloud environment and the secondavailability domain in the second cloud environment are selected basedon a condition associated with the transmission latencies computed forpairs of availability domains.

The condition may correspond to selecting the pair of ADs that resultsin the lowest transmission latencies observed in the iterative processof steps 1765A-1765D. Upon identifying the first availability domain inthe first cloud environment and the second availability domain in thesecond cloud environment, the process may instantiate a desired numberof compute instances in the selected domains to enable a user in thesecond cloud environment to avail of one or more services provided bythe first cloud environment.

Examples of Cloud Infrastructure

As noted above, infrastructure as a service (IaaS) is one particulartype of cloud computing. IaaS can be configured to provide virtualizedcomputing resources over a public network (e.g., the Internet). In anIaaS model, a cloud computing provider can host the infrastructurecomponents (e.g., servers, storage devices, network nodes (e.g.,hardware), deployment software, platform virtualization (e.g., ahypervisor layer), or the like). In some cases, an IaaS provider mayalso supply a variety of services to accompany those infrastructurecomponents (e.g., billing, monitoring, logging, security, load balancingand clustering, etc.). Thus, as these services may be policy-driven,IaaS users may be able to implement policies to drive load balancing tomaintain application availability and performance.

In some instances, IaaS customers may access resources and servicesthrough a wide area network (WAN), such as the Internet, and can use thecloud provider's services to install the remaining elements of anapplication stack. For example, the user can log in to the IaaS platformto create virtual machines (VMs), install operating systems (OSs) oneach VM, deploy middleware such as databases, create storage buckets forworkloads and backups, and even install enterprise software into thatVM. Customers can then use the provider's services to perform variousfunctions, including balancing network traffic, troubleshootingapplication issues, monitoring performance, managing disaster recovery,etc.

In most cases, a cloud computing model will require the participation ofa cloud provider. The cloud provider may, but need not be, a third-partyservice that specializes in providing (e.g., offering, renting, selling)IaaS. An entity might also opt to deploy a private cloud, becoming itsown provider of infrastructure services.

In some examples, IaaS deployment is the process of putting a newapplication, or a new version of an application, onto a preparedapplication server or the like. It may also include the process ofpreparing the server (e.g., installing libraries, daemons, etc.). Thisis often managed by the cloud provider, below the hypervisor layer(e.g., the servers, storage, network hardware, and virtualization).Thus, the customer may be responsible for handling (OS), middleware,and/or application deployment (e.g., on self-service virtual machines(e.g., that can be spun up on demand) or the like.

In some examples, IaaS provisioning may refer to acquiring computers orvirtual hosts for use, and even installing needed libraries or serviceson them. In most cases, deployment does not include provisioning, andthe provisioning may need to be performed first.

In some cases, there are two different problems for IaaS provisioning.First, there is the initial challenge of provisioning the initial set ofinfrastructure before anything is running. Second, there is thechallenge of evolving the existing infrastructure (e.g., adding newservices, changing services, removing services, etc.) once everythinghas been provisioned. In some cases, these two challenges may beaddressed by enabling the configuration of the infrastructure to bedefined declaratively. In other words, the infrastructure (e.g., whatcomponents are needed and how they interact) can be defined by one ormore configuration files. Thus, the overall topology of theinfrastructure (e.g., what resources depend on which, and how they eachwork together) can be described declaratively. In some instances, oncethe topology is defined, a workflow can be generated that creates and/ormanages the different components described in the configuration files.

In some examples, an infrastructure may have many interconnectedelements. For example, there may be one or more virtual private clouds(VPCs) (e.g., a potentially on-demand pool of configurable and/or sharedcomputing resources), also known as a core network. In some examples,there may also be one or more security group rules provisioned to definehow the security of the network will be set up and one or more virtualmachines (VMs). Other infrastructure elements may also be provisioned,such as a load balancer, a database, or the like. As more and moreinfrastructure elements are desired and/or added, the infrastructure mayincrementally evolve.

In some instances, continuous deployment techniques may be employed toenable deployment of infrastructure code across various virtualcomputing environments. Additionally, the described techniques canenable infrastructure management within these environments. In someexamples, service teams can write code that is desired to be deployed toone or more, but often many, different production environments (e.g.,across various different geographic locations, sometimes spanning theentire world). However, in some examples, the infrastructure on whichthe code will be deployed must first be set up. In some instances, theprovisioning can be done manually, a provisioning tool may be utilizedto provision the resources, and/or deployment tools may be utilized todeploy the code once the infrastructure is provisioned.

FIG. 18 is a block diagram 1800 illustrating an example pattern of anIaaS architecture, according to at least one embodiment. Serviceoperators 1802 can be communicatively coupled to a secure host tenancy1804 that can include a virtual cloud network (VCN) 1806 and a securehost subnet 1808. In some examples, the service operators 1802 may beusing one or more client computing devices, which may be portablehandheld devices (e.g., an iPhone®, cellular telephone, an iPad®,computing tablet, a personal digital assistant (PDA)) or wearabledevices (e.g., a Google Glass® head mounted display), running softwaresuch as Microsoft Windows Mobile®, and/or a variety of mobile operatingsystems such as iOS, Windows Phone, Android, BlackBerry 8, Palm OS, andthe like, and being Internet, e-mail, short message service (SMS),Blackberry®, or other communication protocol enabled. Alternatively, theclient computing devices can be general purpose personal computersincluding, by way of example, personal computers and/or laptop computersrunning various versions of Microsoft Windows®, Apple Macintosh®, and/orLinux operating systems. The client computing devices can be workstationcomputers running any of a variety of commercially available UNIX® orUNIX-like operating systems, including without limitation the variety ofGNU/Linux operating systems, such as for example, Google Chrome OS.Alternatively, or in addition, client computing devices may be any otherelectronic device, such as a thin-client computer, an Internet-enabledgaming system (e.g., a Microsoft Xbox gaming console with or without aKinect® gesture input device), and/or a personal messaging device,capable of communicating over a network that can access the VCN 1806and/or the Internet.

The VCN 1806 can include a local peering gateway (LPG) 1810 that can becommunicatively coupled to a secure shell (SSH) VCN 1812 via an LPG 1810contained in the SSH VCN 1812. The SSH VCN 1812 can include an SSHsubnet 1814, and the SSH VCN 1812 can be communicatively coupled to acontrol plane VCN 1816 via the LPG 1810 contained in the control planeVCN 1816. Also, the SSH VCN 1812 can be communicatively coupled to adata plane VCN 1818 via an LPG 1810. The control plane VCN 1816 and thedata plane VCN 1818 can be contained in a service tenancy 1819 that canbe owned and/or operated by the IaaS provider.

The control plane VCN 1816 can include a control plane demilitarizedzone (DMZ) tier 1820 that acts as a perimeter network (e.g., portions ofa corporate network between the corporate intranet and externalnetworks). The DMZ-based servers may have restricted responsibilitiesand help keep security breaches contained. Additionally, the DMZ tier1820 can include one or more load balancer (LB) subnet(s) 1822, acontrol plane app tier 1824 that can include app subnet(s) 1826, acontrol plane data tier 1828 that can include database (DB) subnet(s)1830 (e.g., frontend DB subnet(s) and/or backend DB subnet(s)). The LBsubnet(s) 1822 contained in the control plane DMZ tier 1820 can becommunicatively coupled to the app subnet(s) 1826 contained in thecontrol plane app tier 1824 and an Internet gateway 1834 that can becontained in the control plane VCN 1816, and the app subnet(s) 1826 canbe communicatively coupled to the DB subnet(s) 1830 contained in thecontrol plane data tier 1828 and a service gateway 1836 and a networkaddress translation (NAT) gateway 1838. The control plane VCN 1816 caninclude the service gateway 1836 and the NAT gateway 1838.

The control plane VCN 1816 can include a data plane mirror app tier 1840that can include app subnet(s) 1826. The app subnet(s) 1826 contained inthe data plane mirror app tier 1840 can include a virtual networkinterface controller (VNIC) 1842 that can execute a compute instance1844. The compute instance 1844 can communicatively couple the appsubnet(s) 1826 of the data plane mirror app tier 1840 to app subnet(s)1826 that can be contained in a data plane app tier 1846.

The data plane VCN 1818 can include the data plane app tier 1846, a dataplane DMZ tier 1848, and a data plane data tier 1850. The data plane DMZtier 1848 can include LB subnet(s) 1822 that can be communicativelycoupled to the app subnet(s) 1826 of the data plane app tier 1846 andthe Internet gateway 1834 of the data plane VCN 1818. The app subnet(s)1826 can be communicatively coupled to the service gateway 1836 of thedata plane VCN 1818 and the NAT gateway 1838 of the data plane VCN 1818.The data plane data tier 1850 can also include the DB subnet(s) 1830that can be communicatively coupled to the app subnet(s) 1826 of thedata plane app tier 1846.

The Internet gateway 1834 of the control plane VCN 1816 and of the dataplane VCN 1818 can be communicatively coupled to a metadata managementservice 1852 that can be communicatively coupled to public Internet1854. Public Internet 1854 can be communicatively coupled to the NATgateway 1838 of the control plane VCN 1816 and of the data plane VCN1818. The service gateway 1836 of the control plane VCN 1816 and of thedata plane VCN 1818 can be communicatively couple to cloud services1856.

In some examples, the service gateway 1836 of the control plane VCN 1816or of the data plan VCN 1818 can make application programming interface(API) calls to cloud services 1856 without going through public Internet1854. The API calls to cloud services 1856 from the service gateway 1836can be one-way: the service gateway 1836 can make API calls to cloudservices 1856, and cloud services 1856 can send requested data to theservice gateway 1836. But, cloud services 1856 may not initiate APIcalls to the service gateway 1836.

In some examples, the secure host tenancy 1804 can be directly connectedto the service tenancy 1819, which may be otherwise isolated. The securehost subnet 1808 can communicate with the SSH subnet 1814 through an LPG1810 that may enable two-way communication over an otherwise isolatedsystem. Connecting the secure host subnet 1808 to the SSH subnet 1814may give the secure host subnet 1808 access to other entities within theservice tenancy 1819.

The control plane VCN 1816 may allow users of the service tenancy 1819to set up or otherwise provision desired resources. Desired resourcesprovisioned in the control plane VCN 1816 may be deployed or otherwiseused in the data plane VCN 1818. In some examples, the control plane VCN1816 can be isolated from the data plane VCN 1818, and the data planemirror app tier 1840 of the control plane VCN 1816 can communicate withthe data plane app tier 1846 of the data plane VCN 1818 via VNICs 1842that can be contained in the data plane mirror app tier 1840 and thedata plane app tier 1846.

In some examples, users of the system, or customers, can make requests,for example create, read, update, or delete (CRUD) operations, throughpublic Internet 1854 that can communicate the requests to the metadatamanagement service 1852. The metadata management service 1852 cancommunicate the request to the control plane VCN 1816 through theInternet gateway 1834. The request can be received by the LB subnet(s)1822 contained in the control plane DMZ tier 1820. The LB subnet(s) 1822may determine that the request is valid, and in response to thisdetermination, the LB subnet(s) 1822 can transmit the request to appsubnet(s) 1826 contained in the control plane app tier 1824. If therequest is validated and requires a call to public Internet 1854, thecall to public Internet 1854 may be transmitted to the NAT gateway 1838that can make the call to public Internet 1854. Memory that may bedesired to be stored by the request can be stored in the DB subnet(s)1830.

In some examples, the data plane mirror app tier 1840 can facilitatedirect communication between the control plane VCN 1816 and the dataplane VCN 1818. For example, changes, updates, or other suitablemodifications to configuration may be desired to be applied to theresources contained in the data plane VCN 1818. Via a VNIC 1842, thecontrol plane VCN 1816 can directly communicate with, and can therebyexecute the changes, updates, or other suitable modifications toconfiguration to, resources contained in the data plane VCN 1818.

In some embodiments, the control plane VCN 1816 and the data plane VCN1818 can be contained in the service tenancy 1819. In this case, theuser, or the customer, of the system may not own or operate either thecontrol plane VCN 1816 or the data plane VCN 1818. Instead, the IaaSprovider may own or operate the control plane VCN 1816 and the dataplane VCN 1818, both of which may be contained in the service tenancy1819. This embodiment can enable isolation of networks that may preventusers or customers from interacting with other users', or othercustomers', resources. Also, this embodiment may allow users orcustomers of the system to store databases privately without needing torely on public Internet 1854, which may not have a desired level ofsecurity, for storage.

In other embodiments, the LB subnet(s) 1822 contained in the controlplane VCN 1816 can be configured to receive a signal from the servicegateway 1836. In this embodiment, the control plane VCN 1816 and thedata plane VCN 1818 may be configured to be called by a customer of theIaaS provider without calling public Internet 1854. Customers of theIaaS provider may desire this embodiment since database(s) that thecustomers use may be controlled by the IaaS provider and may be storedon the service tenancy 1819, which may be isolated from public Internet1854.

FIG. 19 is a block diagram 1900 illustrating another example pattern ofan IaaS architecture, according to at least one embodiment. Serviceoperators 1902 (e.g., service operators 1802 of FIG. 18 ) can becommunicatively coupled to a secure host tenancy 1904 (e.g., the securehost tenancy 1804 of FIG. 18 ) that can include a virtual cloud network(VCN) 1906 (e.g., the VCN 1806 of FIG. 18 ) and a secure host subnet1908 (e.g., the secure host subnet 1808 of FIG. 18 ). The VCN 1906 caninclude a local peering gateway (LPG) 1910 (e.g., the LPG 1810 of FIG.18 ) that can be communicatively coupled to a secure shell (SSH) VCN1912 (e.g., the SSH VCN 1812 of FIG. 18 ) via an LPG 1810 contained inthe SSH VCN 1912. The SSH VCN 1912 can include an SSH subnet 1914 (e.g.,the SSH subnet 1814 of FIG. 18 ), and the SSH VCN 1912 can becommunicatively coupled to a control plane VCN 1916 (e.g., the controlplane VCN 1816 of FIG. 18 ) via an LPG 1910 contained in the controlplane VCN 1916. The control plane VCN 1916 can be contained in a servicetenancy 1919 (e.g., the service tenancy 1819 of FIG. 18 ), and the dataplane VCN 1918 (e.g., the data plane VCN 1818 of FIG. 18 ) can becontained in a customer tenancy 1921 that may be owned or operated byusers, or customers, of the system.

The control plane VCN 1916 can include a control plane DMZ tier 1920(e.g. the control plane DMZ tier 1820 of FIG. 18 ) that can include LBsubnet(s) 1922 (e.g. LB subnet(s) 1822 of FIG. 18 ), a control plane apptier 1924 (e.g. the control plane app tier 1824 of FIG. 18 ) that caninclude app subnet(s) 1926 (e.g. app subnet(s) 1826 of FIG. 18 ), acontrol plane data tier 1928 (e.g. the control plane data tier 1828 ofFIG. 18 ) that can include database (DB) subnet(s) 1930 (e.g. similar toDB subnet(s) 1830 of FIG. 18 ). The LB subnet(s) 1922 contained in thecontrol plane DMZ tier 1920 can be communicatively coupled to the appsubnet(s) 1926 contained in the control plane app tier 1924 and anInternet gateway 1934 (e.g. the Internet gateway 1834 of FIG. 18 ) thatcan be contained in the control plane VCN 1916, and the app subnet(s)1926 can be communicatively coupled to the DB subnet(s) 1930 containedin the control plane data tier 1928 and a service gateway 1936 (e.g. theservice gateway of FIG. 18 ) and a network address translation (NAT)gateway 1938 (e.g. the NAT gateway 1838 of FIG. 18 ). The control planeVCN 1916 can include the service gateway 1936 and the NAT gateway 1938.

The control plane VCN 1916 can include a data plane mirror app tier 1940(e.g., the data plane mirror app tier 1840 of FIG. 18 ) that can includeapp subnet(s) 1926. The app subnet(s) 1926 contained in the data planemirror app tier 1940 can include a virtual network interface controller(VNIC) 1942 (e.g., the VNIC of 1842) that can execute a compute instance1944 (e.g., similar to the compute instance 1844 of FIG. 18 ). Thecompute instance 1944 can facilitate communication between the appsubnet(s) 1926 of the data plane mirror app tier 1940 and the appsubnet(s) 1926 that can be contained in a data plane app tier 1946(e.g., the data plane app tier 1846 of FIG. 18 ) via the VNIC 1942contained in the data plane mirror app tier 1940 and the VNIC 1942contained in the data plan app tier 1946.

The Internet gateway 1934 contained in the control plane VCN 1916 can becommunicatively coupled to a metadata management service 1952 (e.g., themetadata management service 1852 of FIG. 18 ) that can becommunicatively coupled to public Internet 1954 (e.g., public Internet1854 of FIG. 18 ). Public Internet 1954 can be communicatively coupledto the NAT gateway 1938 contained in the control plane VCN 1916. Theservice gateway 1936 contained in the control plane VCN 1416 can becommunicatively couple to cloud services 1956 (e.g., cloud services 1856of FIG. 18 ).

In some examples, the data plane VCN 1918 can be contained in thecustomer tenancy 1921. In this case, the IaaS provider may provide thecontrol plane VCN 1916 for each customer, and the IaaS provider may, foreach customer, set up a unique compute instance 1944 that is containedin the service tenancy 1919. Each compute instance 1944 may allowcommunication between the control plane VCN 1916, contained in theservice tenancy 1919, and the data plane VCN 1918 that is contained inthe customer tenancy 1921. The compute instance 1944 may allow resourcesthat are provisioned in the control plane VCN 1916 that is contained inthe service tenancy 1919, to be deployed or otherwise used in the dataplane VCN 1918 that is contained in the customer tenancy 1921.

In other examples, the customer of the IaaS provider may have databasesthat live in the customer tenancy 1921. In this example, the controlplane VCN 1916 can include the data plane mirror app tier 1940 that caninclude app subnet(s) 1926. The data plane mirror app tier 1940 canreside in the data plane VCN 1918, but the data plane mirror app tier1940 may not live in the data plane VCN 1918. That is, the data planemirror app tier 1940 may have access to the customer tenancy 1921, butthe data plane mirror app tier 1940 may not exist in the data plane VCN1918 or be owned or operated by the customer of the IaaS provider. Thedata plane mirror app tier 1940 may be configured to make calls to thedata plane VCN 1918 but may not be configured to make calls to anyentity contained in the control plane VCN 1916. The customer may desireto deploy or otherwise use resources in the data plane VCN 1918 that areprovisioned in the control plane VCN 1916, and the data plane mirror apptier 1940 can facilitate the desired deployment, or other usage ofresources, of the customer.

In some embodiments, the customer of the IaaS provider can apply filtersto the data plane VCN 1918. In this embodiment, the customer candetermine what the data plane VCN 1918 can access, and the customer mayrestrict access to public Internet 1954 from the data plane VCN 1918.The IaaS provider may not be able to apply filters or otherwise controlaccess of the data plane VCN 1918 to any outside networks or databases.Applying filters and controls by the customer onto the data plane VCN1918, contained in the customer tenancy 1921, can help isolate the dataplane VCN 1918 from other customers and from public Internet 1954.

In some embodiments, cloud services 1956 can be called by the servicegateway 1936 to access services that may not exist on public Internet1954, on the control plane VCN 1916, or on the data plane VCN 1918. Theconnection between cloud services 1956 and the control plane VCN 1916 orthe data plane VCN 1918 may not be live or continuous. Cloud services1956 may exist on a different network owned or operated by the IaaSprovider. Cloud services 1956 may be configured to receive calls fromthe service gateway 1936 and may be configured to not receive calls frompublic Internet 1954. Some cloud services 1956 may be isolated fromother cloud services 1956, and the control plane VCN 1916 may beisolated from cloud services 1956 that may not be in the same region asthe control plane VCN 1916. For example, the control plane VCN 1916 maybe located in “Region 1,” and cloud service “Deployment 13,” may belocated in Region 1 and in “Region 2.” If a call to Deployment 13 ismade by the service gateway 1936 contained in the control plane VCN 1916located in Region 1, the call may be transmitted to Deployment 13 inRegion 1. In this example, the control plane VCN 1916, or Deployment 13in Region 1, may not be communicatively coupled to, or otherwise incommunication with, Deployment 13 in Region 2.

FIG. 20 is a block diagram 2000 illustrating another example pattern ofan IaaS architecture, according to at least one embodiment. Serviceoperators 2002 (e.g., service operators 1802 of FIG. 18 ) can becommunicatively coupled to a secure host tenancy 2004 (e.g., the securehost tenancy 1804 of FIG. 18 ) that can include a virtual cloud network(VCN) 2006 (e.g., the VCN 1806 of FIG. 18 ) and a secure host subnet2008 (e.g., the secure host subnet 1808 of FIG. 18 ). The VCN 2006 caninclude an LPG 2010 (e.g., the LPG 1810 of FIG. 18 ) that can becommunicatively coupled to an SSH VCN 2012 (e.g., the SSH VCN 1812 ofFIG. 18 ) via an LPG 2010 contained in the SSH VCN 2012. The SSH VCN2012 can include an SSH subnet 2014 (e.g., the SSH subnet 1814 of FIG.18 ), and the SSH VCN 1812 can be communicatively coupled to a controlplane VCN 2016 (e.g., the control plane VCN 1816 of FIG. 18 ) via an LPG2010 contained in the control plane VCN 2016 and to a data plane VCN2018 (e.g. the data plane 1818 of FIG. 18 ) via an LPG 2010 contained inthe data plane VCN 2018. The control plane VCN 2016 and the data planeVCN 2018 can be contained in a service tenancy 2019 (e.g., the servicetenancy 1819 of FIG. 18 ).

The control plane VCN 1816 can include a control plane DMZ tier 1820(e.g. the control plane DMZ tier 1820 of FIG. 18 ) that can include loadbalancer (LB) subnet(s) 1822 (e.g. LB subnet(s) 1822 of FIG. 18 ), acontrol plane app tier 2024 (e.g. the control plane app tier 1824 ofFIG. 18 ) that can include app subnet(s) 2026 (e.g., similar to appsubnet(s) 1826 of FIG. 18 ), a control plane data tier 2028 (e.g., thecontrol plane data tier 1828 of FIG. 18 ) that can include DB subnet(s)2030. The LB subnet(s) 2022 contained in the control plane DMZ tier 2020can be communicatively coupled to the app subnet(s) 2026 contained inthe control plane app tier 2024 and to an Internet gateway 1834 (e.g.the Internet gateway 1834 of FIG. 18 ) that can be contained in thecontrol plane VCN 2016, and the app subnet(s) 2026 can becommunicatively coupled to the DB subnet(s) 1830 contained in thecontrol plane data tier 1828 and to a service gateway 1836 (e.g. theservice gateway of FIG. 18 ) and a network address translation (NAT)gateway 1838 (e.g. the NAT gateway 1838 of FIG. 18 ). The control planeVCN 2016 can include the service gateway 2036 and the NAT gateway 2038.

The data plane VCN 2018 can include a data plane app tier 2046 (e.g.,the data plane app tier 1846 of FIG. 18 ), a data plane DMZ tier 2048(e.g., the data plane DMZ tier 1848 of FIG. 18 ), and a data plane datatier 2050 (e.g., the data plane data tier 1850 of FIG. 18 ). The dataplane DMZ tier 2048 can include LB subnet(s) 2022 that can becommunicatively coupled to trusted app subnet(s) 2060 and untrusted appsubnet(s) 2062 of the data plane app tier 2046 and the Internet gateway2034 contained in the data plane VCN 2018. The trusted app subnet(s)2060 can be communicatively coupled to the service gateway 2036contained in the data plane VCN 2018, the NAT gateway 2038 contained inthe data plane VCN 2018, and DB subnet(s) 2030 contained in the dataplane data tier 2050. The untrusted app subnet(s) 2062 can becommunicatively coupled to the service gateway 2036 contained in thedata plane VCN 2018 and DB subnet(s) 2030 contained in the data planedata tier 2050. The data plane data tier 2050 can include DB subnet(s)2030 that can be communicatively coupled to the service gateway 2036contained in the data plane VCN 2018.

The untrusted app subnet(s) 2062 can include one or more primary VNICs2064(1)-(N) that can be communicatively coupled to tenant virtualmachines (VMs) 2066(1)-(N). Each tenant VM 2066(1)-(N) can becommunicatively coupled to a respective app subnet 2067(1)-(N) that canbe contained in respective container egress VCNs 2068(1)-(N) that can becontained in respective customer tenancies 2070(1)-(N). Respectivesecondary VNICs 2072(1)-(N) can facilitate communication between theuntrusted app subnet(s) 2062 contained in the data plane VCN 2018 andthe app subnet contained in the container egress VCNs 2068(1)-(N). Eachcontainer egress VCNs 2068(1)-(N) can include a NAT gateway 2038 thatcan be communicatively coupled to public Internet 2054 (e.g., publicInternet 1854 of FIG. 18 ).

The Internet gateway 2034 contained in the control plane VCN 2016 andcontained in the data plane VCN 2018 can be communicatively coupled to ametadata management service 2052 (e.g., the metadata management system1852 of FIG. 18 ) that can be communicatively coupled to public Internet2054. Public Internet 2054 can be communicatively coupled to the NATgateway 2038 contained in the control plane VCN 2016 and contained inthe data plane VCN 2018. The service gateway 2036 contained in thecontrol plane VCN 2016 and contained in the data plane VCN 2018 can becommunicatively couple to cloud services 2056.

In some embodiments, the data plane VCN 2018 can be integrated withcustomer tenancies 2070. This integration can be useful or desirable forcustomers of the IaaS provider in some cases such as a case that maydesire support when executing code. The customer may provide code to runthat may be destructive, may communicate with other customer resources,or may otherwise cause undesirable effects. In response to this, theIaaS provider may determine whether to run code given to the IaaSprovider by the customer.

In some examples, the customer of the IaaS provider may grant temporarynetwork access to the IaaS provider and request a function to beattached to the data plane tier app 2046. Code to run the function maybe executed in the VMs 2066(1)-(N), and the code may not be configuredto run anywhere else on the data plane VCN 2018. Each VM 2066(1)-(N) maybe connected to one customer tenancy 2070. Respective containers2071(1)-(N) contained in the VMs 2066(1)-(N) may be configured to runthe code. In this case, there can be a dual isolation (e.g., thecontainers 2071(1)-(N) running code, where the containers 2071(1)-(N)may be contained in at least the VM 2066(1)-(N) that are contained inthe untrusted app subnet(s) 2062), which may help prevent incorrect orotherwise undesirable code from damaging the network of the IaaSprovider or from damaging a network of a different customer. Thecontainers 2071(1)-(N) may be communicatively coupled to the customertenancy 2070 and may be configured to transmit or receive data from thecustomer tenancy 2070. The containers 2071(1)-(N) may not be configuredto transmit or receive data from any other entity in the data plane VCN2018. Upon completion of running the code, the IaaS provider may kill orotherwise dispose of the containers 2071(1)-(N).

In some embodiments, the trusted app subnet(s) 2060 may run code thatmay be owned or operated by the IaaS provider. In this embodiment, thetrusted app subnet(s) 2060 may be communicatively coupled to the DBsubnet(s) 2030 and be configured to execute CRUD operations in the DBsubnet(s) 2030. The untrusted app subnet(s) 2062 may be communicativelycoupled to the DB subnet(s) 2030, but in this embodiment, the untrustedapp subnet(s) may be configured to execute read operations in the DBsubnet(s) 2030. The containers 2071(1)-(N) that can be contained in theVM 2066(1)-(N) of each customer and that may run code from the customermay not be communicatively coupled with the DB subnet(s) 2030.

In other embodiments, the control plane VCN 2016 and the data plane VCN2018 may not be directly communicatively coupled. In this embodiment,there may be no direct communication between the control plane VCN 2016and the data plane VCN 2018. However, communication can occur indirectlythrough at least one method. An LPG 2010 may be established by the IaaSprovider that can facilitate communication between the control plane VCN2016 and the data plane VCN 2018. In another example, the control planeVCN 2016 or the data plane VCN 2018 can make a call to cloud services2056 via the service gateway 2036. For example, a call to cloud services2056 from the control plane VCN 2016 can include a request for a servicethat can communicate with the data plane VCN 2018.

FIG. 21 is a block diagram 2100 illustrating another example pattern ofan IaaS architecture, according to at least one embodiment. Serviceoperators 2102 (e.g., service operators 1802 of FIG. 18 ) can becommunicatively coupled to a secure host tenancy 2104 (e.g., the securehost tenancy 1804 of FIG. 18 ) that can include a virtual cloud network(VCN) 2106 (e.g., the VCN 1806 of FIG. 18 ) and a secure host subnet2108 (e.g., the secure host subnet 1808 of FIG. 18 ). The VCN 2106 caninclude an LPG 2110 (e.g., the LPG 1810 of FIG. 18 ) that can becommunicatively coupled to an SSH VCN 2112 (e.g., the SSH VCN 1812 ofFIG. 18 ) via an LPG 2110 contained in the SSH VCN 2112. The SSH VCN2112 can include an SSH subnet 2114 (e.g., the SSH subnet 1814 of FIG.18 ), and the SSH VCN 2112 can be communicatively coupled to a controlplane VCN 2116 (e.g., the control plane VCN 1816 of FIG. 18 ) via an LPG2110 contained in the control plane VCN 2116 and to a data plane VCN2118 (e.g., the data plane 1818 of FIG. 18 ) via an LPG 2110 containedin the data plane VCN 2118. The control plane VCN 2116 and the dataplane VCN 2118 can be contained in a service tenancy 2119 (e.g., theservice tenancy 1819 of FIG. 18 ).

The control plane VCN 2116 can include a control plane DMZ tier 2120(e.g. the control plane DMZ tier 1820 of FIG. 18 ) that can include LBsubnet(s) 2122 (e.g. LB subnet(s) 1822 of FIG. 18 ), a control plane apptier 2124 (e.g. the control plane app tier 1824 of FIG. 18 ) that caninclude app subnet(s) 2126 (e.g. app subnet(s) 1826 of FIG. 18 ), acontrol plane data tier 2128 (e.g., the control plane data tier 1828 ofFIG. 18 ) that can include DB subnet(s) 2130 (e.g. DB subnet(s) 2030 ofFIG. 20 ). The LB subnet(s) 2122 contained in the control plane DMZ tier2120 can be communicatively coupled to the app subnet(s) 2126 containedin the control plane app tier 2124 and to an Internet gateway 2134(e.g., the Internet gateway 1834 of FIG. 18 ) that can be contained inthe control plane VCN 2116, and the app subnet(s) 2126 can becommunicatively coupled to the DB subnet(s) 2130 contained in thecontrol plane data tier 2128 and to a service gateway 2136 (e.g., theservice gateway of FIG. 18 ) and a network address translation (NAT)gateway 2138 (e.g., the NAT gateway 1838 of FIG. 18 ). The control planeVCN 2116 can include the service gateway 2136 and the NAT gateway 2138.

The data plane VCN 2118 can include a data plane app tier 2146 (e.g.,the data plane app tier 1846 of FIG. 18 ), a data plane DMZ tier 2148(e.g., the data plane DMZ tier 2148 of FIG. 18 ), and a data plane datatier 2150 (e.g., the data plane data tier 1850 of FIG. 18 ). The dataplane DMZ tier 2148 can include LB subnet(s) 2122 that can becommunicatively coupled to trusted app subnet(s) 2160 (e.g., trusted appsubnet(s) 2060 of FIG. 20 ) and untrusted app subnet(s) 2162 (e.g.,untrusted app subnet(s) 2062 of FIG. 20 ) of the data plane app tier2146 and the Internet gateway 2134 contained in the data plane VCN 2118.The trusted app subnet(s) 2160 can be communicatively coupled to theservice gateway 2136 contained in the data plane VCN 2118, the NATgateway 2138 contained in the data plane VCN 2118, and DB subnet(s) 2130contained in the data plane data tier 2150. The untrusted app subnet(s)2162 can be communicatively coupled to the service gateway 2136contained in the data plane VCN 2118 and DB subnet(s) 2130 contained inthe data plane data tier 2150. The data plane data tier 2150 can includeDB subnet(s) 2130 that can be communicatively coupled to the servicegateway 2136 contained in the data plane VCN 2118.

The untrusted app subnet(s) 2162 can include primary VNICs 2164(1)-(N)that can be communicatively coupled to tenant virtual machines (VMs)2166(1)-(N) residing within the untrusted app subnet(s) 2162. Eachtenant VM 2166(1)-(N) can run code in a respective container 2167(1)-(N)and be communicatively coupled to an app subnet 2126 that can becontained in a data plane app tier 2146 that can be contained in acontainer egress VCN 2168. Respective secondary VNICs 2172(1)-(N) canfacilitate communication between the untrusted app subnet(s) 2162contained in the data plane VCN 2118 and the app subnet contained in thecontainer egress VCN 2168. The container egress VCN can include a NATgateway 2138 that can be communicatively coupled to public Internet 2154(e.g., public Internet 1854 of FIG. 18 ).

The Internet gateway 2134 contained in the control plane VCN 2116 andcontained in the data plane VCN 2118 can be communicatively coupled to ametadata management service 2152 (e.g., the metadata management system1852 of FIG. 18 ) that can be communicatively coupled to public Internet2154. Public Internet 2154 can be communicatively coupled to the NATgateway 2138 contained in the control plane VCN 2116 and contained inthe data plane VCN 2118. The service gateway 2136 contained in thecontrol plane VCN 2116 and contained in the data plane VCN 2118 can becommunicatively couple to cloud services 2156.

In some examples, the pattern illustrated by the architecture of blockdiagram 2100 of FIG. 21 may be considered an exception to the patternillustrated by the architecture of block diagram 2000 of FIG. 20 and maybe desirable for a customer of the IaaS provider if the IaaS providercannot directly communicate with the customer (e.g., a disconnectedregion). The respective containers 2167(1)-(N) that are contained in theVMs 2166(1)-(N) for each customer can be accessed in real-time by thecustomer. The containers 2167(1)-(N) may be configured to make calls torespective secondary VNICs 2172(1)-(N) contained in app subnet(s) 2126of the data plane app tier 2146 that can be contained in the containeregress VCN 2168. The secondary VNICs 2172(1)-(N) can transmit the callsto the NAT gateway 2138 that may transmit the calls to public Internet2154. In this example, the containers 2167(1)-(N) that can be accessedin real-time by the customer can be isolated from the control plane VCN2116 and can be isolated from other entities contained in the data planeVCN 2118. The containers 2167(1)-(N) may also be isolated from resourcesfrom other customers.

In other examples, the customer can use the containers 2167(1)-(N) tocall cloud services 2156. In this example, the customer may run code inthe containers 2167(1)-(N) that requests a service from cloud services2156. The containers 2167(1)-(N) can transmit this request to thesecondary VNICs 2172(1)-(N) that can transmit the request to the NATgateway that can transmit the request to public Internet 2154. PublicInternet 2154 can transmit the request to LB subnet(s) 2122 contained inthe control plane VCN 2116 via the Internet gateway 2134. In response todetermining the request is valid, the LB subnet(s) can transmit therequest to app subnet(s) 2126 that can transmit the request to cloudservices 2156 via the service gateway 2136.

It should be appreciated that IaaS architectures 1800, 1900, 2000, 2100depicted in the figures may have other components than those depicted.Further, the embodiments shown in the figures are only some examples ofa cloud infrastructure system that may incorporate an embodiment of thedisclosure. In some other embodiments, the IaaS systems may have more orfewer components than shown in the figures, may combine two or morecomponents, or may have a different configuration or arrangement ofcomponents.

In certain embodiments, the IaaS systems described herein may include asuite of applications, middleware, and database service offerings thatare delivered to a customer in a self-service, subscription-based,elastically scalable, reliable, highly available, and secure manner. Anexample of such an IaaS system is the Oracle Cloud Infrastructure (OCI)provided by the present assignee.

FIG. 22 illustrates an example computer system 2200, in which variousembodiments of the present disclosure may be implemented. The system2200 may be used to implement any of the computer systems describedabove. As shown in the figure, computer system 2200 includes aprocessing unit 2204 that communicates with a number of peripheralsubsystems via a bus subsystem 2202. These peripheral subsystems mayinclude a processing acceleration unit 2206, and I/O subsystem 2208, astorage subsystem 2218 and a communications subsystem 2224. Storagesubsystem 2218 includes tangible computer-readable storage media 2222and a system memory 2210.

Bus subsystem 2202 provides a mechanism for letting the variouscomponents and subsystems of computer system 2200 communicate with eachother as intended. Although bus subsystem 2202 is shown schematically asa single bus, alternative embodiments of the bus subsystem may utilizemultiple buses. Bus subsystem 2202 may be any of several types of busstructures including a memory bus or memory controller, a peripheralbus, and a local bus using any of a variety of bus architectures. Forexample, such architectures may include an Industry StandardArchitecture (ISA) bus, Micro Channel Architecture (MCA) bus, EnhancedISA (EISA) bus, Video Electronics Standards Association (VESA) localbus, and Peripheral Component Interconnect (PCI) bus, which can beimplemented as a Mezzanine bus manufactured to the IEEE P1386.1standard.

Processing unit 2204, which can be implemented as one or more integratedcircuits (e.g., a conventional microprocessor or microcontroller),controls the operation of computer system 2200. One or more processorsmay be included in processing unit 2204. These processors may includesingle core or multicore processors. In certain embodiments, processingunit 2204 may be implemented as one or more independent processing units2232 and/or 2234 with single or multicore processors included in eachprocessing unit. In other embodiments, processing unit 2204 may also beimplemented as a quad-core processing unit formed by integrating twodual-core processors into a single chip.

In various embodiments, processing unit 2204 can execute a variety ofprograms in response to program code and can maintain multipleconcurrently executing programs or processes. At any given time, some,or all of the program code to be executed can be resident inprocessor(s) 2204 and/or in storage subsystem 2218. Through suitableprogramming, processor(s) 2204 can provide various functionalitiesdescribed above. Computer system 2200 may additionally include aprocessing acceleration unit 2206, which can include a digital signalprocessor (DSP), a special-purpose processor, and/or the like.

I/O subsystem 2208 may include user interface input devices and userinterface output devices. User interface input devices may include akeyboard, pointing devices such as a mouse or trackball, a touchpad ortouch screen incorporated into a display, a scroll wheel, a click wheel,a dial, a button, a switch, a keypad, audio input devices with voicecommand recognition systems, microphones, and other types of inputdevices. User interface input devices may include, for example, motionsensing and/or gesture recognition devices such as the Microsoft Kinect®motion sensor that enables users to control and interact with an inputdevice, such as the Microsoft Xbox® 360 game controller, through anatural user interface using gestures and spoken commands. Userinterface input devices may also include eye gesture recognition devicessuch as the Google Glass® blink detector that detects eye activity(e.g., ‘blinking’ while taking pictures and/or making a menu selection)from users and transforms the eye gestures as input into an input device(e.g., Google Glass®). Additionally, user interface input devices mayinclude voice recognition sensing devices that enable users to interactwith voice recognition systems (e.g., Siri® navigator), through voicecommands.

User interface input devices may also include, without limitation, threedimensional (3D) mice, joysticks or pointing sticks, gamepads andgraphic tablets, and audio/visual devices such as speakers, digitalcameras, digital camcorders, portable media players, webcams, imagescanners, fingerprint scanners, barcode reader 3D scanners, 3D printers,laser rangefinders, and eye gaze tracking devices. Additionally, userinterface input devices may include, for example, medical imaging inputdevices such as computed tomography, magnetic resonance imaging,position emission tomography, medical ultrasonography devices. Userinterface input devices may also include, for example, audio inputdevices such as MIDI keyboards, digital musical instruments and thelike.

User interface output devices may include a display subsystem, indicatorlights, or non-visual displays such as audio output devices, etc. Thedisplay subsystem may be a cathode ray tube (CRT), a flat-panel device,such as that using a liquid crystal display (LCD) or plasma display, aprojection device, a touch screen, and the like. In general, use of theterm “output device” is intended to include all possible types ofdevices and mechanisms for outputting information from computer system2200 to a user or other computer. For example, user interface outputdevices may include, without limitation, a variety of display devicesthat visually convey text, graphics, and audio/video information such asmonitors, printers, speakers, headphones, automotive navigation systems,plotters, voice output devices, and modems.

Computer system 2200 may comprise a storage subsystem 2218 thatcomprises software elements, shown as being currently located within asystem memory 2210. System memory 2210 may store program instructionsthat are loadable and executable on processing unit 2204, as well asdata generated during the execution of these programs.

Depending on the configuration and type of computer system 2200, systemmemory 2210 may be volatile (such as random-access memory (RAM)) and/ornon-volatile (such as read-only memory (ROM), flash memory, etc.) TheRAM typically contains data and/or program modules that are immediatelyaccessible to and/or presently being operated and executed by processingunit 2204. In some implementations, system memory 2210 may includemultiple different types of memory, such as static random-access memory(SRAM) or dynamic random-access memory (DRAM). In some implementations,a basic input/output system (BIOS), containing the basic routines thathelp to transfer information between elements within computer system2200, such as during start-up, may typically be stored in the ROM. Byway of example, and not limitation, system memory 2210 also illustratesapplication programs 2212, which may include client applications, Webbrowsers, mid-tier applications, relational database management systems(RDBMS), etc., program data 2214, and an operating system 2216. By wayof example, operating system 2216 may include various versions ofMicrosoft Windows®, Apple Macintosh®, and/or Linux operating systems, avariety of commercially available UNIX® or UNIX-like operating systems(including without limitation the variety of GNU/Linux operatingsystems, the Google Chrome® OS, and the like) and/or mobile operatingsystems such as iOS, Windows® Phone, Android® OS, BlackBerry® 17 OS, andPalm® OS operating systems.

Storage subsystem 2218 may also provide a tangible computer-readablestorage medium for storing the basic programming and data constructsthat provide the functionality of some embodiments. Software (programs,code modules, instructions) that when executed by a processor providethe functionality described above may be stored in storage subsystem2218. These software modules or instructions may be executed byprocessing unit 2204. Storage subsystem 2218 may also provide arepository for storing data used in accordance with the presentdisclosure.

Storage subsystem 2200 may also include a computer-readable storagemedia reader 2220 that can further be connected to computer-readablestorage media 2222. Together and optionally, in combination with systemmemory 2210, computer-readable storage media 2222 may comprehensivelyrepresent remote, local, fixed, and/or removable storage devices plusstorage media for temporarily and/or more permanently containing,storing, transmitting, and retrieving computer-readable information.

Computer-readable storage media 2222 containing code, or portions ofcode, can also include any appropriate media known or used in the art,including storage media and communication media, such as but not limitedto, volatile and non-volatile, removable and non-removable mediaimplemented in any method or technology for storage and/or transmissionof information. This can include tangible computer-readable storagemedia such as RAM, ROM, electronically erasable programmable ROM(EEPROM), flash memory or other memory technology, CD-ROM, digitalversatile disk (DVD), or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or other tangible computer readable media. This can also includenontangible computer-readable media, such as data signals, datatransmissions, or any other medium which can be used to transmit thedesired information, and which can be accessed by computing system 2200.

By way of example, computer-readable storage media 2222 may include ahard disk drive that reads from or writes to non-removable, nonvolatilemagnetic media, a magnetic disk drive that reads from or writes to aremovable, nonvolatile magnetic disk, and an optical disk drive thatreads from or writes to a removable, nonvolatile optical disk such as aCD ROM, DVD, and Blu-Ray® disk, or other optical media.Computer-readable storage media 2222 may include, but is not limited to,Zip® drives, flash memory cards, universal serial bus (USB) flashdrives, secure digital (SD) cards, DVD disks, digital video tape, andthe like. Computer-readable storage media 2222 may also include,solid-state drives (SSD) based on non-volatile memory such asflash-memory based SSDs, enterprise flash drives, solid state ROM, andthe like, SSDs based on volatile memory such as solid-state RAM, dynamicRAM, static RAM, DRAM-based SSDs, magneto resistive RAM (MRAM) SSDs, andhybrid SSDs that use a combination of DRAM and flash memory based SSDs.The disk drives and their associated computer-readable media may providenon-volatile storage of computer-readable instructions, data structures,program modules, and other data for computer system 2200.

Communications subsystem 2224 provides an interface to other computersystems and networks. Communications subsystem 2224 serves as aninterface for receiving data from and transmitting data to other systemsfrom computer system 2200. For example, communications subsystem 2224may enable computer system 2200 to connect to one or more devices viathe Internet. In some embodiments communications subsystem 2224 caninclude radio frequency (RF) transceiver components for accessingwireless voice and/or data networks (e.g., using cellular telephonetechnology, advanced data network technology, such as 3G, 4G or EDGE(enhanced data rates for global evolution), Wi-Fi (IEEE 802.11 familystandards, or other mobile communication technologies, or anycombination thereof), global positioning system (GPS) receivercomponents, and/or other components. In some embodiments communicationssubsystem 2224 can provide wired network connectivity (e.g., Ethernet)in addition to or instead of a wireless interface.

In some embodiments, communications subsystem 2224 may also receiveinput communication in the form of structured and/or unstructured datafeeds 2226, event streams 2228, event updates 2230, and the like onbehalf of one or more users who may use computer system 2200.

By way of example, communications subsystem 2224 may be configured toreceive data feeds 2226 in real-time from users of social networksand/or other communication services such as Twitter® feeds, Facebook®updates, web feeds such as Rich Site Summary (RSS) feeds, and/orreal-time updates from one or more third party information sources.

Additionally, communications subsystem 2224 may also be configured toreceive data in the form of continuous data streams, which may includeevent streams 2228 of real-time events and/or event updates 2230 thatmay be continuous or unbounded in nature with no explicit end. Examplesof applications that generate continuous data may include, for example,sensor data applications, financial tickers, network performancemeasuring tools (e.g., network monitoring and traffic managementapplications), clickstream analysis tools, automobile trafficmonitoring, and the like.

Communications subsystem 2224 may also be configured to output thestructured and/or unstructured data feeds 2226, event streams 2228,event updates 2230, and the like to one or more databases that may be incommunication with one or more streaming data source computers coupledto computer system 2200.

Computer system 2200 can be one of various types, including a handheldportable device (e.g., an iPhone® cellular phone, an iPad® computingtablet, a PDA), a wearable device (e.g., a Google Glass® head mounteddisplay), a PC, a workstation, a mainframe, a kiosk, a server rack, orany other data processing system.

Due to the ever-changing nature of computers and networks, thedescription of computer system 2200 depicted in the figure is intendedonly as a specific example. Many other configurations having more orfewer components than the system depicted in the figure are possible.For example, customized hardware might also be used and/or particularelements might be implemented in hardware, firmware, software (includingapplets), or a combination. Further, connection to other computingdevices, such as network input/output devices, may be employed. Based onthe disclosure and teachings provided herein, a person of ordinary skillin the art will appreciate other ways and/or methods to implement thevarious embodiments.

Although specific embodiments of the disclosure have been described,various modifications, alterations, alternative constructions, andequivalents are also encompassed within the scope of the disclosure.Embodiments of the present disclosure are not restricted to operationwithin certain specific data processing environments but are free tooperate within a plurality of data processing environments.Additionally, although embodiments of the present disclosure have beendescribed using a particular series of transactions and steps, it shouldbe apparent to those skilled in the art that the scope of the presentdisclosure is not limited to the described series of transactions andsteps. Various features and aspects of the above-described embodimentsmay be used individually or jointly.

Further, while embodiments of the present disclosure have been describedusing a particular combination of hardware and software, it should berecognized that other combinations of hardware and software are alsowithin the scope of the present disclosure. Embodiments of the presentdisclosure may be implemented only in hardware, or only in software, orusing combinations thereof. The various processes described herein canbe implemented on the same processor or different processors in anycombination. Accordingly, where components or modules are described asbeing configured to perform certain operations, such configuration canbe accomplished, e.g., by designing electronic circuits to perform theoperation, by programming programmable electronic circuits (such asmicroprocessors) to perform the operation, or any combination thereof.Processes can communicate using a variety of techniques including butnot limited to conventional techniques for inter process communication,and different pairs of processes may use different techniques, or thesame pair of processes may use different techniques at different times.

The specification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense. It will, however, beevident that additions, subtractions, deletions, and other modificationsand changes may be made thereunto without departing from the broaderspirit and scope as set forth in the claims. Thus, although specificdisclosure embodiments have been described, these are not intended to belimiting. Various modifications and equivalents are within the scope ofthe following claims.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the disclosed embodiments (especially in thecontext of the following claims) are to be construed to cover both thesingular and the plural, unless otherwise indicated herein or clearlycontradicted by context. The terms “comprising,” “having,” “including,”and “containing” are to be construed as open-ended terms (i.e., meaning“including, but not limited to,”) unless otherwise noted. The term“connected” is to be construed as partly or wholly contained within,attached to, or joined together, even if there is something intervening.Recitation of ranges of values herein are merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range, unless otherwise indicated herein and eachseparate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate embodiments of the disclosure anddoes not pose a limitation on the scope of the disclosure unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe disclosure.

Disjunctive language such as the phrase “at least one of X, Y, or Z,”unless specifically stated otherwise, is intended to be understoodwithin the context as used in general to present that an item, term,etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y,and/or Z). Thus, such disjunctive language is not generally intended to,and should not, imply that certain embodiments require at least one ofX, at least one of Y, or at least one of Z to each be present.

Preferred embodiments of this disclosure are described herein, includingthe best mode known to the inventors for carrying out the disclosure.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate and the inventors intend for the disclosure to be practicedotherwise than as specifically described herein. Accordingly, thisdisclosure includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the disclosure unlessotherwise indicated herein or otherwise clearly contradicted by context.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein. In the foregoing specification, aspects of the disclosure aredescribed with reference to specific embodiments thereof, but thoseskilled in the art will recognize that the disclosure is not limitedthereto. Various features and aspects of the above-described disclosuremay be used individually or jointly. Further, embodiments can beutilized in any number of environments and applications beyond thosedescribed herein without departing from the broader spirit and scope ofthe specification. The specification and drawings are, accordingly, tobe regarded as illustrative rather than restrictive.

What is claimed is:
 1. A method comprising: receiving, by a multi-cloudinfrastructure included in a first cloud environment, a request tocreate a network-link between a first virtual network in the first cloudenvironment and a second virtual network in a second cloud environment,the first virtual network in the first cloud environment beingpreviously created to enable a user associated with a customer tenancyin the second cloud environment to access one or more services providedin the first cloud environment; and creating the network-link betweenthe first virtual network in the first cloud environment and the secondvirtual network in the second cloud environment using a plurality oflink-enabling virtual networks, wherein a first link-enabling virtualnetwork from the plurality of link-enabling virtual networks is placedin the second cloud environment and a second link-enabling virtualnetwork from the plurality of link-enabling virtual networks is placedin the first cloud environment.
 2. The method of claim 1, wherein eachof the first link-enabling virtual network in the second cloudenvironment and the second link-enabling virtual network in the firstcloud environment is assigned a unique classless inter-domain routing IPaddress space.
 3. The method of claim 1, wherein the first link-enablingvirtual network in the second cloud environment and the secondlink-enabling virtual network in the first cloud environment are createdfor each customer tenancy of a plurality of customer tenancies of thesecond cloud environment.
 4. The method of claim 1, wherein the firstlink-enabling virtual network encapsulates traffic received from thesecond virtual network in the second cloud environment to generateencapsulated traffic, the encapsulated traffic being transmitted by thefirst link-enabling virtual network to a hub virtual network included inthe second cloud environment.
 5. The method of claim 1, wherein thefirst link-enabling virtual network includes a first pair of virtualnetwork adaptors, each of which is configured to encapsulate trafficreceived from the second virtual network in the second cloud environmentto generate encapsulated traffic.
 6. The method of claim 4, wherein thehub virtual network included in the second cloud environment includes apair of virtual network forwarders, each of which is configured toperform a network address translation for the encapsulated trafficreceived from the first link-enabling virtual network to forward theencapsulated traffic to a hub virtual network included in the firstcloud environment.
 7. The method of claim 1, wherein the secondlink-enabling virtual network in the first cloud environment includes asecond pair of virtual network adaptors, each of which is configured todecapsulate, encapsulated traffic received from a hub virtual networkincluded in the second cloud environment.
 8. The method of claim 1,wherein a hub virtual network included in the second cloud environmentis communicatively coupled to a hub virtual network included in thefirst cloud environment by a high-bandwidth interconnect link.
 9. Themethod of claim 8, wherein the hub virtual network included in the firstcloud environment includes a VNIC that is communicatively coupled to thesecond link-enabling virtual network in the first cloud environment. 10.The method of claim 1, wherein the second link-enabling virtual networkin the first cloud environment, forwards traffic to the first virtualnetwork in the first cloud environment via a dynamic routing gateway.11. One or more computer readable non-transitory media storingcomputer-executable instructions that, when executed by one or moreprocessors, cause: receiving, by a multi-cloud infrastructure includedin a first cloud environment, a request to create a network-link betweena first virtual network in the first cloud environment and a secondvirtual network in a second cloud environment, the first virtual networkin the first cloud environment being previously created to enable a userassociated with a customer tenancy in the second cloud environment toaccess one or more services provided in the first cloud environment; andcreating the network-link between the first virtual network in the firstcloud environment and the second virtual network in the second cloudenvironment using a plurality of link-enabling virtual networks, whereina first link-enabling virtual network from the plurality oflink-enabling virtual networks is placed in the second cloud environmentand a second link-enabling virtual network from the plurality oflink-enabling virtual networks is placed in the first cloud environment.12. The one or more computer readable non-transitory media storingcomputer-executable instructions of claim 11, wherein each of the firstlink-enabling virtual network in the second cloud environment and thesecond link-enabling virtual network in the first cloud environment isassigned a unique classless inter-domain routing IP address space. 13.The one or more computer readable non-transitory media storingcomputer-executable instructions of claim 11, wherein the firstlink-enabling virtual network in the second cloud environment and thesecond link-enabling virtual network in the first cloud environment arecreated for each customer tenancy of a plurality of customer tenanciesof the second cloud environment.
 14. The one or more computer readablenon-transitory media storing computer-executable instructions of claim11, wherein the first link-enabling virtual network encapsulates trafficreceived from the second virtual network in the second cloud environmentto generate encapsulated traffic, the encapsulated traffic beingtransmitted by the first link-enabling virtual network to a hub virtualnetwork included in the second cloud environment.
 15. The one or morecomputer readable non-transitory media storing computer-executableinstructions of claim 11, wherein the first link-enabling virtualnetwork includes a first pair of virtual network adaptors, each of whichis configured to encapsulate traffic received from the second virtualnetwork in the second cloud environment to generate encapsulatedtraffic.
 16. The one or more computer readable non-transitory mediastoring computer-executable instructions of claim 14, wherein the hubvirtual network included in the second cloud environment includes a pairof virtual network forwarders, each of which is configured to perform anetwork address translation for the encapsulated traffic received fromthe first link-enabling virtual network to forward the encapsulatedtraffic to a hub virtual network included in the first cloudenvironment.
 17. The one or more computer readable non-transitory mediastoring computer-executable instructions of claim 11, wherein the secondlink-enabling virtual network in the first cloud environment includes asecond pair of virtual network adaptors, each of which is configured todecapsulate, encapsulated traffic received from a hub virtual networkincluded in the second cloud environment.
 18. The one or more computerreadable non-transitory media storing computer-executable instructionsof claim 11, wherein a hub virtual network included in the second cloudenvironment is communicatively coupled to a hub virtual network includedin the first cloud environment by a high-bandwidth interconnect link.19. A computing device comprising: one or more processors; and a memoryincluding instructions that, when executed with the one or moreprocessors, cause the computing device to, at least: receive, by amulti-cloud infrastructure included in a first cloud environment, arequest to create a network-link between a first virtual network in thefirst cloud environment and a second virtual network in a second cloudenvironment, the first virtual network in the first cloud environmentbeing previously created to enable a user associated with a customertenancy in the second cloud environment to access one or more servicesprovided in the first cloud environment; and create the network-linkbetween the first virtual network in the first cloud environment and thesecond virtual network in the second cloud environment using a pluralityof link-enabling virtual networks, wherein a first link-enabling virtualnetwork from the plurality of link-enabling virtual networks is placedin the second cloud environment and a second link-enabling virtualnetwork from the plurality of link-enabling virtual networks is placedin the first cloud environment.
 20. The computing device of claim 19,wherein each of the first link-enabling virtual network in the secondcloud environment and the second link-enabling virtual network in thefirst cloud environment is assigned a unique classless inter-domainrouting IP address space.